SAN ANTONIO (Reuters) – A rancher who served as mayor of a Texas town for 63 years and was thought to be the longest-serving mayor in the United States has died in office at age 92, city officials said on Wednesday. Hilmar Moore died on Tuesday night at a local hospital of complications from a fall last month, said Garry Gillen, a city commissioner in Richmond, located southwest of Houston. “He had a real sense for the history of Texas,” Gillen said. “He embodied that Texas cowboy tradition. I think that’s what kept him in office, was his sense of loyalty to the land and service to the people. …