Silas Reynolds was born in 1750 in New England, most likely Connecticut.  He was brought to New York state by his parents when he was an infant.  At the beginning of the Revolutionary War, he was living in a village called Smith's Cove, Orange County, NY, later named Monroe, and was one of the "Signers of the Association in Cornwall, Embracing Monroe, Cornwall, Bloominggrove, 1775," their declaration of independence.  His name also appears in a list of signers of a "Committee of Safety for Cornwall Precinct, Orange County."

Growing up in a frontier settlement during the 1750s presented many hardships, particularly since Orange County was involved in the French and Indian War of 1755, supplying troops and provisions, plus defense of homes against Indian raids.   Undoubtedly the Reynolds boys learned all the arts of survival necessary to that time and place as well as many crafts at which they were later to make a living.  Perhaps they worked at the mines extracting iron ore or in the iron works that produced the iron of the great chain across the Hudson River during the Revolution in an attempt to stop the British ships.  And of course they learned about farming, which was essential for survival.

In 1774 or 1775, Silas married Sarah (Sally) Thorpe.

Before 1798, Silas and Sarah moved to Goshen, Orange County, New York where in 1798, a son, John A. Reynolds, was born.