Historical Research Guide

How to find historical information about the places you care about

Welcome to our guide to researching historic properties in the City of Los Angeles (of course, some of the resources listed here will also provide information about other cities as well). This guide is broken down into sections based on typical research needs.

You might need to use all of these sections (i.e. if you’re preparing a landmark nomination) or just one (i.e. if you’re looking for specific information, such as a construction date). Some research must be conducted in person, while a growing amount of information is online. Each section addresses both types of resources if available.

If you find any information that is out of date or incorrect (or if you know of resources that we’ve missed), don’t hesitate to get in touch with the Conservancy at (213) 623-2489 or Good luck!

Researching the Site

A legal description typically includes tract, block, and lot/parcel numbers. It will be useful later in the research process to identify your property when searching for relevant documents. The legal description is available from the County Assessor’s Office but can be easily accessed from the Assessor’s website as well.

Los Angeles County Assessor’s Office
Hall of Administration
500 W. Temple St. Room 225
(213) 974-3211

In addition to the legal description, the Assessor’s Office and website can provide the following information:

  • Property information
  • Recent sale information
  • Most recent roll values
  • Legal description
  • Building description, including the year constructed for many properties.

From the main page of the website: 

  • Click on “View Property Maps & Data”
  • Agree to the disclaimer (if you agree with it)
  • Type the property address you wish to research and click submit (Note: The system is very particular about how the address is typed. Omit “W., S., Street, Blvd., etc. Instead, type the street number and street name. Example – 3540 Figueroa, instead of 3540 S. Figueroa St.)
  • Your search may return multiple results. Click on the Assessor’s Identification Number (AIN) corresponding to your address (also take note of the AIN).
  • To the right will appear a panel containing the information listed above. To the left is a basic parcel map. You may click on “View Assessor’s Map” to view a more detailed map of the property’s area.
  • After pulling up the Assessor’s map, note the Map Book Number, usually denoted by the initials MB followed by a string of digits. It is usually found directly underneath the tract name or number. If there is more than one, take down both, as your property may exist on multiple tracts. This information will be necessary when searching for tract maps at the Bureau of Engineering. (Note: the first number in the MB No. denotes the map book, and the second number denotes the page number or numbers on which the tract map is located within the map book)

Additional information can be found by visiting the Assessor’s main office in downtown Los Angeles.

Tract maps offer detailed information about the location of the property and the area surrounding it. They may also give you information about the original owner of the land on which your property is located and previous subdivisions of the land.

Original tract maps are available from the Bureau of Engineering’s Records Department. Many tract maps are also available on the Bureau of Engineering’s website and can be accessed using the Assessor’s Identification Number (AIN) or the Map Book Number (MB No.).

Los Angeles Bureau of Engineering
Central Records
Public Works Building
1149 S. Broadway, #B-10
Los Angeles, CA 90015
(213) 847-0700

Tract maps at the records department of the engineering bureau are available on a microfilm aperture card format. To access these records:

  • Visit the public counter at the records department of the engineering bureau.
  • Provide the staff with the MB number that you recorded from the assessor’s map.
  • A staff member will pull up the corresponding aperture cards containing the property’s original and more recent tract maps.
  • The aperture cards can be viewed on the viewers in the office’s public area.
  • Printouts of the tract maps are available for a printing and processing fee.

Original tract maps often are accompanied by tract descriptions that may include the names of the original owners of the tract on which your property is located and the subdivisions of this land. This description usually begins “Being a subdivision of…” and is usually found under the tract name or number on the map or on an accompanying page if it is a detailed description.

The Bureau of Engineering has made an extensive effort to make as many of its documents available to the public through its online electronic vault.

In addition to tract maps, many more documents that may be useful are available for viewing on aperture cards at the Bureau of Engineering Records Department.

Researching the Building

Building Permit

Department of Building and Safety
Records Department
201 N. Figueroa St. Room 110
Los Angeles, CA 90012
(213) 482-6899

Online building records are also available and can be searched by address, legal decription, assessor number, etc.


6262 Van Nuys Blvd. Room 251
Van Nuys, CA 91401
(818) 374-4390

Building permits allow you to trace the complete history of construction done on the property. Building permits typically provide you with the following information:

  • Date construction was completed
  • Owner of the resource at time of construction
  • Purpose of the building
  • Number of rooms
  • Valuation of the building when it was built
  • Size of the building
  • Architect
  • Builder
  • Number of stories
  • Material of construction

In addition to the above, you can find certificates of occupancy and alteration permits that show changes made in the building.

All of the above listed documents can be found in the Records Department at the Department of Building and Safety. Building permits are viewable on microfilm and electronically through the department’s IDIS (Internet Document Imaging System), and copies are available for a fee.

In general, blueprints and other drawings are not available for single-family homes or commercial structures under three stories that were built before 1978. A charge is assessed for any documents you request.

To obtain building permit by fax or to order copies for pick-up: 

  • Download the request form.
  • Submit by fax to:
    • Downtown office – (213) 482-6862
    • Van Nuys office – (818) 374-5013
  • Allow 7-10 days for your request to be processed. You can request that copies be faxed to you or left for pick-up at the office closest to you.

To obtain building permits in person (same-day service): 

  • You must first take a number and fill out a research request form.
  • When your number is called, a staff member will use your property’s address to pull up an index of existing building permits and other documents. (See Appendix 2)
  • Looking at the index, you will be able to identify those permits of interest. Usually, the most useful permits are those for the original construction of the building. You can locate this permit by looking at the second column, titled subtype, of the index.  The third column contains the date the permits were issued while the fourth column lists the permit number assigned to each permit.
  • Once you have identified the documents that you wish to view, the staff member at the counter will direct supporting staff to retrieve copies using the microfilm or electronically through the department’s IDIS system.  Your number will be called after copies of the requested permits or related documents have been made.
  • Alternatively, if you are familiar with using the department’s microfilm or electronic IDIS system, you can request to perform your own permit searches.

The document index provided is very helpful for tracing a complete history of work completed on your property. Some properties may have extended alteration and addition histories, whiles others, you may find, have had very little work done.

Los Angeles Central Library
History Department
630 W. Fifth St.
Los Angeles, CA 90071

Sanborn insurance maps were created to assist fire insurance companies in assessing the risk associated with insuring a particular property. They list street blocks and building numbers, including numbers in use at the time the map was made as well as previous numbers. These maps were made between 1867 and 1970.

To view editions of these maps for California communities, visit the History Department at the Los Angeles Central Library. The library owns maps for the entire state of California in its set of Sanborn Maps on microfilm, ranging from 1888 to 1950 on 72 reels. They are catalogued under the number NR 912.794 S198, and are shelved in the microfilm drawers at the far end of the reading room. There is a guide to the Sanborn Map collection available at the reference desk, which is necessary in order to determine the reel on which your map is located.

The Los Angeles Sanborns cover four basic time periods:

  • 1888 – original covering a small portion of downtown
  • 1894 – Slightly expanded downtown area
  • 1906 to 1930 – As the area grew and the Sanborn coverage expanded. These volumes exist in their original form. The date of first issue is listed right after the volume number, for example vol. 7 1907. This time frame extends from 1907 to 1930 when the last volumes were completed. This begins at the end of reel 20 and continues to reel 27.
  • 1950 – As changes were made in the covered areas the changes were reflected by pastings which were applied by Sanborn representatives. The final set of the Library of Congress are corrected atlases as they looked in 1950. Most architects and urban planners need to look at this set which begins at reel 28 and continues to reel 34.

A second set of Sanborns now available at the library covers only Los Angeles City from the 1950s through the 1960s and a few maps into the 1970s. This set does not cover outlying cities such as Santa Monica, Pasadena, or the City of Industry, etc. These are shelved after the early Sanborns in the microfilm drawer.

To find Sanborn Maps:

  • There are 40 volumes covering Los Angeles Proper, so you must first determine the volume that covers your desired property’s area.
  • Check the large General Index to Sanborn Maps at the reference desk for the volume number and sheet number on which your property’s area is located. The index is organized by street name, and differentiates between North, South, East, West, Street, Avenue, etc. If you are unsure of the exact address of your property (which you shouldn’t be, by this point) you can check the Thomas Guide index to Sanborns, also available at the reference desk.
  • Once you’ve determined the volume and sheet number, you must next find out on which reel your map is located. This can be done by checking the Guide to Sanborns at the front desk. Look under the pages tabbed “ Los Angeles” for the appropriate reel.
  • Go to the cabinet housing the reels and find the appropriate reel. Its contents can be viewed using the adjacent microfilm readers.

A library card gives you access to California Sanborns through the Los Angeles Public Library’s website.

  • From the main page of the library’s website, click on “Research & Homework.”
  • You will be prompted to enter your library card number and PIN.
  • A long list of alphabetically organized databases will be displayed. Locate and click on “Sanborn Maps.”
  • On the Sanborn website’s main page, click on “Browse Maps.” Follow the step-by-step instructions to locate your property.

Be sure to check with the Map Librarian – the LAPL collection contains other maps that may be of use.

Researching the People and Events Associated with the Building

Office of the County Clerk Los Angeles County Registrar-Recorder
Land Records Division 12400 E. Imperial Hwy. Norwalk, CA 90650
201 N. Figueroa St. Room 730 Los Angeles, CA 90012
(800) 815-2666
(213) 977-6014

The Land Records Division keeps records of grant deeds, which document transfer of ownership of a piece of property. Easily accessible at the County Clerk’s office is information about the current owner of a piece of property. By accessing this information, you can begin to track the history of ownership of your property by pulling previous deeds on the property. A deed names both a grantor and a grantee. A grantor is the person selling the property. A grantee is the person purchasing or receiving the property. Looking at the most recent deed available on the property, you can identify the grantor to the current owner. At some point, this grantor was the grantee of the property. Locate the deed on which this person is listed as the grantee. By following this process, you can gain a complete history of the ownership of your property.

When tracing deeds chronologically, you may encounter gaps due to foreclosure, tax sales, or other problems.

To obtain deeds:

  • Visit the office of the Land Records Division.
  • Provide the staff member with either the property address, the Assessor’s Identification Number, or the legal description.
  • The staff member will pull up an index of deeds available on your property. Identify those deeds that will be useful, and the staff member will pull the deeds.

Once you have traced the ownership of your property comes the task of determining whether the previous owners were of any importance within the Los Angeles community.

Los Angeles Central Library
History Department
630 W. Fifth St.
Los Angeles, CA 90071
(213) 228-7400

Once you have compiled a chronology of ownership for your property, there are many resources available for biographical and historical research on the previous owners. This information is important in assessing the historic or cultural value of your property.
The Central Library contains a variety of useful research sources. Resources for biographical research are extensive, as you can reference city directories, newspaper archives, vital records, or books such as “Who’s Who” which give brief biographies of Los Angeles citizens.

Here is a list of resources available in the History/Genealogy Department at the Central Library:

  • “Who’s Who” books
  • Telephone Directories (dating back to 1900)
  • City Directories (in book and microfilm formats)
  • Los Angeles Times Historical Archive
  • Photograph Collection
  • Genealogy Collection
  • Census Records from 1790
  • Family Histories
  • Heraldry and Coats of Arms
  • Immigration Records and passenger arrival lists for New York, Philadelphia, and Boston. The library has records of passenger lists for San Pedro/Wilmington/ Los Angeles for 1907-1948.
  • All available naturalization records for the U.S. District Court for southern California
  • Local histories including cemetery records, probate records, and town records
  • Military records – The department owns substantially complete rosters of soldiers who served in the Revolutionary War, the War of 1812, and the Civil War. In addition, there are several hundred unit histories of military units from World Wars I and II, Korea, and Vietnam.
  • Name books – There are approximately 600 books on names, their derivation and meaning. There is no master index and many titles are in other languages.
  • Newspapers – The library owns on microfilm all of the Los Angeles Times from 1881, the complete Herald Examiner, the New York Times from 1851, the Times of London from 1785, the San Francisco Chronicle from 1869, and the Chicago Tribune from 1849-1998.

Searching for information on an individual can be time consuming and at times return few results. The above is only a listing of what is available at the Central Library. There are many additional resources throughout the city.

Los Angeles County Registrar-Recorder
12400 E. Imperial Hwy.
Norwalk, CA 90650
(800) 815-2666

Birth, death, and marriage records for Los Angeles County are available through the County Registrar’s office. Birth records are available from 1866, death records are available from 1877, and marriage licenses from 1852.

The County Registrar-Recorder’s process for requesting these records is somewhat complicated and expensive. It is up to the researcher to decide whether or not he or she feels that the information gained will be valuable in determining the property’s significance. Detailed information on requesting these records can be found at the Registrar-Recorder’s website.

Requests for unofficial records can be made by mail or in person. An in-person request requires a valid photo I.D., and can only be fulfilled same-day if the birth occurred after 1964. Births occurring before 1964 will be mailed within 15 working days.

To request records by mail, you must submit a written request containing the person’s name, date of birth (if known) or range of years to be checked, number of copies needed, and relationship to the person whose record you are requesting. Because of the likelihood that you are not related to the person whose record you are requesting, simply state no relation. A relationship is only required if you are requesting a certified official copy of the record. The application can be found on the registrar-recorder’s website. You must also submit a notarized certificate of identity, which can also be found on the website.

Los Angeles Public Library Website

The Los Angeles Public Library’s newspaper archives are magnificent resources for the historic researcher.

The Historical Los Angeles Times Archive is available online to anyone with a library card. While the format is scanned newspaper articles, it is nonetheless easy to search by keyword.

To search the archive:

  • Visit the mainpage of the Los Angeles Public Library’s Website.
  • Click on “Databases.”
  • Type in your library card number and PIN.
  • An alphabetical listing of available databases will be displayed. Locate and click on “Research Library (Proquest).”
  • Click on “Historical Los Angeles Times.”
  • Perform your search. In order to view the articles, you must have installed Adobe Acrobat Reader. Which is available free of charge at

Additional Resources

City Archives 
555 Ramirez St. Space 320
Los Angeles, CA 90012

The city archives serve as the final repository for records of enduring political, economic, legal, and cultural value. They contain a rich, diverse collection of historical records from various city agencies.


ProQuest is an online information database that allows users to search for news articles and other published material, such as journals. It is accessible on the Los Angeles Public Library’s website (with a valid library card) through the “Databases” link. Find ProQuest in the alphabetical database list under “Research Library (ProQuest).” ProQuest has information about everything – not just Los Angeles.

Los Angeles Public Library Photo Collection

A great collection of over 3 million historic photographs from the city of Los Angeles, many of which are available for viewing and ordering online at the library’s website.

Los Angeles Public Library Databases

Many of the library’s databases are accessible through the library’s website, and offer a wealth of historic information that can be directly accessed or by visiting the library itself.


USC School of Architecture Library
Watt Hall
University Park Campus
Los Angeles, CA 90089
(213) 740-1956

The library houses over 75,000 volumes in the areas of architecture, landscape architecture, and urban design. The architecture periodical collection is the most extensive in southern California.


USC Regional History Collection 
University Park Campus
Doheny Memorial Library, Special Collections
Los Angeles, CA 90089
(213) 821-2366

Contains a variety of documents relating to Southern California history, including clippings from the Los Angeles Examiner, and an extensive photograph collection.

California Historical Society 
678 Mission St.
San Francisco, CA 94105
(415) 357-1848