Lydia Longacre came from a prominent New York family. Her grandfather was James Barton Longacre, engraver to the United States Mint, and her father was Reverend Andrew Longacre, minister at the Madison Avenue Methodist Church. Both men had also been successful miniaturists. Lydia exhibited regularly with the American Society of Miniature Painters, and the Old Lyme Art Association, an American art colony founded in 1876 that embraced the impressionist style that American artists had encountered on trips abroad. Her work won numerous awards, including the Levantia White Boardman award in 1949 for best miniature.