Amos Slaymaker was born in London Lands, Pennsylvania. He built and operated a hotel on the Philadelphia and Lancaster Turnpike. During the Revolutionary War, he served as an ensign in the company of Capt. John Slaymaker. He was a member of an association formed for the suppression of Tory activities in Lancaster County, Pennsylvania. He served as justice of the peace of Salisbury Township, Pennsylvania, and county commissioner from 1806 to 1810. He served in the Pennsylvania State Senate in 1810 and 1811.