Lewis, was born in Cardiff, Wales, and in 1734 moved to Whitestone, New York. He worked as a mercantile agent, and was taken prisoner and shipped in a box to France while servicing as a British Mercantile Agent in 1756.
Lewis, later became a member of a number of Political organizations, including the Committee of Sixty (an organization formed for action in opposition to the British), the New York Provincial Congress, and New York's delegate to the Continental Congress in 1775. He was one of the signers of the Declaration of Independence in 1776, as a representative of New York.
Lewis signed the US Articles of Confederation in 1778. He then served as Chairman of the Continental Board of Admiralty.
His Whitestone, home (in what is now Whitestone, Queens, New York) was destroyed during the American Revolution by the British.
Lewis died on December 30, 1803 at the age of 90.
A number of his descendants held prominent roles, including: His son, Morgan Lewis, who was eventually New York State Governor; his great-grandson, Manning Livingston, who died at Gettysburg during the US Civil War; and his great-great-great grandson was a Hollywood director, William A. Wellman.