The X-Patents are all the patents issued by the United States Patent and Trademark Office from July 1790 (when the first U.S. patent was issued), to July 1836. The actual number is unknown, but the best estimate is 9,957. The records were burned in a fire, in December 1836, while in temporary storage. No copies or rosters were maintained by the government at the time, leaving only the inventors’ copies to reconstruct the collection.
On July 31, 1790 inventor Samuel Hopkins of Pittsford, Vermont became the first person to be issued a patent in the United States. His patented invention was an improvement in the “making of Pot Ash by a new apparatus & process.” The earliest patent law required that a working model of each invention be produced in miniature.
The Patent Law was revised for the first time in 1793. It adopted a simple registration system where a patent would be granted for a $30 fee. The Patent Board was replaced by a clerk in the Department of State. James Madison, Secretary of State, created a separate Patent Office within the State Department and he appointed Dr. William Thornton as its first superintendent in May 1802.
The Patent Office was the only major government building to survive the British invasion of Washington, D.C. during the War of 1812. This is credited to Dr. William Thornton who was building a musical instrument in the same building. He persuaded British officers that they would be destroying the shared intellectual record of mankind if the patents were burned.
The disastrous fire occurred on December 15, 1836, when the patents were in temporary storage while a new (more fireproof) facility was being built. A fire station was located next to the temporary storage facility, but the hoses and pumps were frozen, and the firemen were unable to prevent the loss.
The United States Congress immediately passed a law to aid re-issuing of the missing patents after the fire. About 2,800 such patents have been recovered, and 1,989 are online.
Following the 1836 fire, a serial numbering system was instituted. This system is still in use today. When an earlier patent was recovered and re-issued, the USPTO sometimes gave it a fractional number (eg. 2960½X, issued on June 2, 1818; 8736¾X, issued on March 27, 1835) to preserve the correct sequence. Most, but not all, fractional patents are X-Patents.
Prior to this, U.S. patents were identified by titles and dates. Since then, all new patents issued are preserved and given a serial patent number started from 1. The recovered patents are also numbered from 1, however, these numbers have an “X” added to them. The X is generally added to the end of the number except for the first patent which has the X in the beginning of the number. Therefore, they are called X-Patents.
|1X||Potash production||Samuel Hopkins||July 31 1790|
|72X||Cotton Gin||Eli Whitney||March 14 1794|
|4378X||Gas Or Vapor Engine||Samuel Morey||April 1 1826|
|9000X||Grate||N. Winslow||July 2 1836|
|9899X||Brick Machine||C. Waterman||July 2 1836|
|9894X||Plow Moldboard||I. Snider||July 2 1836|
|9893X||Lock||A. Roff||July 2 1836|
|9890X||Thrashing Mach.||A. Parson||July 2 1836|
|9889X||Cook Stove||W. Parmalee||July 2 1836|
|9887X||Plow||T. Miller||July 2 1836|
|9886X||Dressing Stares||C. McGregory||July 2 1836|
|9885X||Cotton Gin||J. McCreight||July 2 1836|
|9884X||Door Lock||J. Mo Clory||July 2 1836|
|9882X||Clover Huller||W. Loomis||July 2 1836|
|9879X||Feather Dresser||F.P.Knowlton||July 2 1836|
|9878X||Platform Balance||J. Horton||July 2 1836|
|9877X||Nail Extractor||R. Haynes||July 2 1836|
|9876X||Cotton Press||H.G. Guyon||July 2 1836|
|9875X||Cook Stove||C. Granger||July 2 1836|