Born in Providence, Rhode Island, Sharpe signed on to a 5 year apprenticeship in 1848 under Joseph R. Brown, to learn to be a watchmaker. His father paid a fee of $50 a year plus $2.50 a week for board. Sharpe made his own set of watchmaker's tools and built his watchmaker's lathe. In addition to mechanical skills, he soon demonstrated administrative ability. He wrote business letters for Brown, some in French. When the apprenticeship was completed, he was made a partner in J. R. Brown & Sharpe. Disturbed by the confusion of gages for measuring the thickness of wire and sheet metal, Sharpe led the development of what became the standard American Wire Gage. He also developed the Brown & Sharpe apprentice program that became the model for such programs. Woodbury has written that "it was Brown who was the mechanical genius and Sharpe who was the outstanding businessman, but one who thoroughly understood, appreciated, and encouraged the work Brown was doing."