TICONDEROGA A Ticonderoga businessman pleaded guilty to sexually abusing a 15-year-old girl in Essex County Court Feb. 26. James T. Gilbert, 34, of 84 Montcalm St., Ticonderoga ,entered guilty pleas in Essex County Court to felony third-degree criminal sexual act, misdemeanor third-degree sexual abuse and endangering the welfare of a child. He had been indicted by an Essex County grand jury last year. The had been placed in the care of Gilbert and his wife, who have since separated, by a private agency. He will be sentenced April 15. Gilbert is free on his own recognizance until sentencing. At the time of his arrest, Gilbert was president of the Essex County Industrial Development Agency, but he resigned from that and several other boards and community-service committees soon afterward. Gilbert owns the Evolve Business Center in Ticonderoga, a computer sales and service company.