A Singer sewing machine's serial number reflects the year of its manufacture. Machines with serial numbers beginning with numerals were manufactured before 1900. Machines with serial numbers beginning with a single letter were manufactured from 1900 to 1935. Serial numbers on machines manufactured after 1935 begin with double letters.
The Singer Company was established in 1851 as I.M. Singer & Co. by Isaac Singer, who secured the patent for the first practical sewing machine. The name was changed to the Singer Company in 1963. Singer was the first company to produce zig-zag and electronic sewing machines. As of 2015, the Singer Company is based in La Vergne, Tennessee and is a subsidiary of SVP Worldwide.