Illinois Watch Serial Number List
| serial number | year | serial number | year | serial number | year |
| 15,000 | 1872 | 465,000 | 1891 | 3,800,000 | 1910 |
| 37,000 | 1873 | 478,000 | 1892 | 3,900,000 | 1911 |
| 59,000 | 1874 | 531,000 | 1893 | 4,000,000 | 1912 |
| 81,000 | 1875 | 575,000 | 1894 | 4,070,000 | 1913 |
| 103,000 | 1876 | 600,000 | 1895 | 4,150,000 | 1914 |
| 125,000 | 1877 | 680,000 | 1896 | 4,220,000 | 1915 |
| 147,000 | 1878 | 760,000 | 1897 | 4,230,000 | 1916 |
| 169,000 | 1879 | 840,000 | 1898 | 4,240,000 | 1917 |
| 191,000 | 1880 | 920,000 | 1899 | 4,250,000 | 1918 |
| 210,000 | 1881 | 1,000,000 | 1900 | 4,300,000 | 1919 |
| 230,000 | 1882 | 1,280,000 | 1901 | 4,400,000 | 1920 |
| 250,000 | 1883 | 1,560,000 | 1902 | 4,500,000 | 1921 |
| 270,000 | 1884 | 1,846,000 | 1903 | 4,683,000 | 1922 |
| 285,000 | 1885 | 2,120,000 | 1904 | 4,866,000 | 1923 |
| 300,000 | 1886 | 2,460,000 | 1905 | 5,049,000 | 1924 |
| 333,000 | 1887 | 2,600,000 | 1906 | 5,232,000 | 1925 |
| 366,000 | 1888 | 2,940,000 | 1907 | 5,415,000 | 1926 |
| 399,000 | 1889 | 3,220,000 | 1908 | 5,600,000 | 1927 |
| 432,000 | 1890 | 3,520,000 | 1909 |
These are approximate production dates. Oftentimes, a block of serial numbers would be assigned and the movement plates blanked out; then the plates would be stored in the warehouse and finished as demand required. So, it is possible that a watch could have been completed some years after the serial number date.