William Colon enlisted on 23 Jan 1865 at Springfield, Illinois, at the age of 18. He was mustered out on 10 Oct 1865 at Fort Snelling, Minnesota. He is listed in the muster rolls as 5' 8" tall, dark complexion, grey eyes, black hair, occupation Farmer.

The Colon family migrated from the Hudson Valley in New York, to Livingston County, Illinois, about 1860. William's parents were William and Annetje (Anne) (Quakkenbosch) Colon, both natives of New York. William had five sisters. He married Jennie Heafey in 1871, and they had four sons and three daughters.