U.S. Patent Records as a Genealogical Resource

In 1790, the United States Congress passed a bill establishing the Patent Board, an entity responsible for conferring rights to inventors for their inventions, a process known as “issuing patents.” Prior to this time, colonies and states issued some patents, either as private acts or in accordance with state or colony-level laws, until the federal government eventually saw the need for a national patent system. Patent files can reveal many details about an ancestor, such as employment information, the nature of his or her work, intellectual abilities, socioeconomic status, and the names of business associates and family members. Although often overlooked, patent records can be valuable genealogical resources.

Patent files are held at the National Archives and Records Administration’s regional facility in Kansas City, Missouri. They are part of Record Group 241, Records of the Patent and Trademark Office, and are separated into two categories: reconstructed files (for patents originally issued before 1837) and patent files (for patents issued between 1837 and 1978). Post-1978 patent files have not yet been transferred into the custody of the National Archives, and remain with the United States Patent and Trademark Office (USPTO).

Reconstructed Files
A fire in December of 1836 destroyed close to 10,000 patent files. Later, about one quarter of these files were partially reconstructed when some inventors sent in their own patent documents or certified copies of them, or recreated documents in accordance with their original patent’s specifications. In these cases, the patents were re-issued to the inventors, and the newly created files were assigned a number ending with the letter “X.” Today, these patent files are known as X-Patents, and can include the following records related to patents that were granted before the fire:

  • copies of patent certificates
  • copies of documents related to patents that were submitted by inventors between 1837 and 1883
  • patent documents and drawings that were re-created between 1837 and 1847

Since no index or inventory was kept prior to the fire, there is no comprehensive list of patent files that were lost and not reconstructed. Most of these early patents were for mechanical devices related to farming and agriculture.

Patent Files
Shortly after the fire, the Patent Office established a numbering system. When an inventor applied for a patent, he or she was assigned a serial number. If a patent was issued, it was assigned a patent number. (The abovementioned pre-1837 patent files that were reconstructed follow this same numbering system, but those patent numbers end with an “X.”)

The files include a variety of records, including the inventor’s petition, application, and oath; correspondence between the patent office and the inventor and/or his or her attorney; and various drawings, diagrams, and descriptions related to the invention (known as letters patent). The files do not include records created after the patent was issued, with the exception of notations of related legal action. If legal action took place regarding the patent, the case could have been heard in a number of federal courts—the District, Appellate, and Supreme courts, or the Court of Customs and Patent Appeals.

Patent drawing for William Morgan Johnson's Safety Guard for Presses


Patent drawing for William Morgan Johnson’s Safety Guard for Presses

Finding Patent Files
The patent files held at the National Archives in Kansas City are filed sequentially by patent number, and the patent number must be known to access the file. Patent numbers can be found through Google Patents, a search engine that has made all issued patents and many patent applications dating back to 1790 searchable by keyword. Most patents can be easily found by searching for the inventor’s name, residence, or employer using the simple search function, but Google Patents also has an advanced search platform that permits searches by patent title, original assignee, date, or other criteria. Google Patents makes it easy to see whether any previous patents were cited in a patent’s application, and whether any subsequent patents relied on the patent of interest. Using optical character recognition technology, Google Patents has transcribed the text from approved patents and patent applications, but the transcriptions are not always reliable. Scans of these documents can be downloaded for free via Google Patents. They are also available through the USPTO website. It is important to note that neither Google Patents or the USPTO website provide full patent files—only the patents and patent applications. A full patent file includes additional records about the inventor and the invention.

Full patent files can be viewed in person or ordered from the National Archives in Kansas City. For in-person viewing, files must be requested two business days in advance so they can be retrieved from an off-site facility. To request a quote for photocopies or digital copies of a file, email the patent number, inventor’s name, and date of filing to kansascity.archives@nara.gov.

In addition to the patent files held in Kansas City, other types of records related to patents and patent applications can be found at National Archives II in College Park, Maryland, including architectural and engineering drawings, photographs, artifacts, maps, and charts. For more details, researchers should consult the National Archives Catalog for a list of other holdings in Record Group 124.

View the full patent file for William Morgan Johnson’s Safety Guard for Presses, patented in 1923.

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