Son of Johannes and Maria (Clarkson) Crolius.
Born: Before December 12, 1753 in New York City, New York.
Christening: December 12, 1753 Reformed Dutch Church, New York City, New York.
Died: 1830 in Unknown.
Married:Mary "Polly" Dobbs February 28, 1775 in Unknown.

William Crolius was born in 1753, among the eldest of a 20+ year span of children of John Crolius and Maria Clarkson. The family lived in Reade Street in New York City, 100 feet west of Centre Street, and operated a pottery established by William's grandfather (possibly the first pottery in New York).

William Crolius married Mary Dobbs, daughter of Captain William Dobbs, in 1775, shortly before the Revolutionary War. William served during the War, including battles at Harlem Heights and White Plains, as assistant harbor master under his father-in-law, and in charge of provisions. He spent much of the war obtaining and delivering provisions for the Army, traveling all around the New York countryside, sometimes at great cost to his health. During one winter, his feet were injured from frost, a lifelong injury. His superiors at one point asked him to desist to save his health, but his dedication to supplying garrisons that were in dire need inspired him to persevere. (His war service is extensively documented in engaging detail in personal narrative statements by both himself and his wife found in pension application records.)

After the war, he returned to the pottery business, possibly setting up shop in Newark. He and his wife had at least two children. He lived to age 76, leaving a widow and at least one surviving son when he died in 1830.