Salem was enslaved by John Bourne, and became known as Salem Bourne. He served in the Continental Army in 1778. He married Peggy in 1784, and they had a son Sheppard in 1787.
"John Bourne owned one by the name of Salem. He was always called Salem Bourne. He had another called Pompey." Bourne, p. 409
On April 24th, 1784, "Salem a Negro formerly a Servant to Capt. John Bourne & Peg a Negro formerly a servant to Mr Edward Emerson, both of Wells, intend marriage"
"Sheppard the Son of Salem Bourne a Negro & Peggy his Wife was born May 2nd, 1787."
Per two Revolutionary War record cards (below), he was raised on April 20, 1778 for the 1st company of York to go to Fishkill. Age 23.
Bibliography:
The History of Wells and Kennebunk from the Earliest Settlement to the Year 1820 - by Edward Bourne (1875)
Massachusetts soldiers and sailors of the Revolutionary War - Office of the Secretary of State (1896)
Massachusetts, Revolutionary War, Index Cards to Muster Rolls, 1775-1783 - FamilySearch.org
Wells, ME: Vital Records, 1737-1841 (Online database: AmericanAncestors.org, New England Historic Genealogical Society, 2016), (Handwritten transcription of original records by Joshua Hubbard, "Copy of births, marriages & deaths taken from Wells town books of record", 1860, R. Stanton Avery Special Collections Department, NEHGS, Boston, MA) https://www.americanancestors.org/DB1689/i/39960/44/1044296696
"Haiti and the Atlantic World" website (https://haitidoi.com/) - https://haitidoi.com/wp-content/uploads/2016/08/shepherd-bourn-miscellaneous-correspondence-regarding-impressed-seamen-nara-rg-59.pdf