Collectors.Org Reference Library: U. S. Patent Dates

U. S. Patent Dates

Invention patent numbers, often found imprinted or stamped on items, or pieces of items, can often be a major clue in dating the item. Remember, however, that patent date does not mean manufactured date. Use the patent number/date only as a guide. (An invention patent is in effect, with exclusive rights for the inventor, for 17 years from date of issuance.)

Year	Starting #	Year	Starting #	Year	Starting #	Year	Starting #	Year	Starting #
1836	1	1837	110	1838	546	1839	1,061	1840	1,465
1841	1,923	1842	2,413	1843	2,901	1844	3,395	1845	3,873
1846	4,348	1847	4,914	1848	5,409	1849	5,993	1850	6,981
1851	7,865	1852	8,622	1853	9,512	1854	10,358	1855	12,117
1856	14,009	1857	16,324	1858	19,010	1859	22,477	1860	26,642
1861	31,005	1862	34,045	1863	37,266	1864	41,047	1865	45,685
1866	51,784	1867	60,658	1868	72,959	1869	85,503	1870	98,460
1871	110,617	1872	122,304	1873	134,504	1874	146,120	1875	158,350
1876	171,641	1877	185,813	1878	198,733	1879	211,078	1880	223,211
1881	236,137	1882	251,685	1883	269,820	1884	291,016	1885	310,163
1886	333,494	1887	355,291	1888	375,720	1889	395,305	1890	418,665
1891	443,987	1892	466,315	1893	488,976	1894	511,744	1895	531,619
1896	552,502	1897	574,369	1898	596,467	1899	616,871	1900	640,167
1901	664,827	1902	690,385	1903	717.521	1904	748,567	1905	778,834
1906	808,618	1907	839,799	1908	875,679	1909	908,436	1910	945,010
1911	980,178	1912	1,013,095	1913	1,049,326	1914	1,083,267	1915	1,123,212
1916	1,166,419	1917	1,210,389	1918	1,251,458	1919	1,290,027	1920	1,326,899
1921	1,364,063	1922	1,401,948	1923	1,440,362	1924	1,478,996	1925	1,521,590
1926	1,568,040	1927	1,612,700	1928	1,654,521	1929	1,696,897	1930	1,742,181
1931	1,787,424	1932	1,839,190	1933	1,892,663	1934	1,941,449	1935	1,985,878
1936	2,026,516	1937	2,066,309	1938	2,104,004	1939	2,142,080	1940	2,185,170
1941	2,227,418	1942	2,268,540	1943	2,307,007	1944	2,338,081	1945	2,366,154
1946	2,391,856	1947	2,413,675	1948	2,433,824	1949	2,457,797	1950	2,492,944
1951	2,536,016	1952	2,580,379	1953	2,624,046	1954	2,664,562	1955	2,698,434
1956	2,728,913	1957	2,775,762	1958	2,818,567	1959	2,866,973	1960	2,919,443
1961	2,966,681	1962	3,015,103	1963	3,070,801	1964	3,116,487	1965	3,163,865
1966	3,226,729	1967	3,295,143	1968	3,360,800	1969	3,419,907	1970	3,487,470
1971	3,551,909	1972	3,631,539	1973	3,707,729	1974	3,781,914	1975	3,858,241
1976	3,930,271	1977	4,000,520	1978	4,065,812	1979	4,131,952	1980	4,180,867
1981	4,242,757	1982	4,308,622	1983	4,366,579	1984	4,423,523	1985	4,490,885
1986	4,562,596	1987	4,633,526	1988	4,716,594	1989	4,794,652	1990	4,890,335
1991	4,980,927	1992	5,077,836	1993	5,175,886	1994	5,274,846	1995	5,377,359
1996	5,479,658	1997	5,589,860	1998	5,704,062	1999	5,855,021	2000	6,009,555
2001	6,167,569	2002	6,334,220	2003	6,502,244	2004	6,671,884	2005	6,836,899
2006	6,981,282	2007	7,155,746	2008	7,313,829	2009		2010