The following data is extracted from Genealogy and Biography of Ontario County, New York.
Gideon, son of Launcelot Granger, was born in Suffield, Connecticut, July 19. 1767, and was the first of the name to make his home in Canandaigua. New York. We are not familiar with the details of his early life except that he was given opportunity to obtain a liberal education, of which he availed himself, graduating from Yale College in 1787, at the age of twenty. He entered upon the study of the law soon afterward, and rose to distinction in the bar of his native state. He was a man of public spirit, and imbued with the jeffersonian principles of free government. He was early and deeply impressed with the importance of the most energetic work for the advancement of the public school system, and was one of the foremost laborers for the establishment of the public school fund in Connecticut, giving liberally himself towards its foundation, and being often called its father. While still a young man his reputation had reached the national capital, and in 1801 he was called by President Jefferson to take a position in his cabinet as postmaster-general. For thirteen years he filled that honorable and responsible office. during which period he was instrumental in the rapid development of the great postal system of the country. His administration of the office continued through both of Mr. Jefferson's terms as president, and most of Mr. Madison's. On his retirement from Washington in 1814, he settled in Canandaigua, whither his reputation had preceded him, and where he was at once accorded the station to which his abilities entitled him. In 1820 he was elected to the state senate, and in that body served two years. He promptly took a leading position as a legislator, and became conspicuous in co-operation with Governor DeWitt Clinton in promoting the great system of internal improvements of which the Erie Canal was the most important feature. In 1821 he retired from public life, and died December 31, 1822, at the comparatively early age of fifty-five years, leaving a record of a career distinguished for its purity, its spotless integrity. and its devotion to the public good. He married Mindwell Pease.
Source: Genealogy and Biography of Ontario County, New York