 Johnson was born in Guilford, Connecticut, the son of a fulling miller, Samuel Johnson Sr., and great-grandson of Robert Johnson, a founder of New Haven Colony, Connecticut.But it was his grandfather William Johnson, a state assemblyman, village clerk, grammar school teacher, mapmaker, militia leader, judge, and church deacon who most influenced him.His grandfather taught him English at age four, and Hebrew at five; he would take young Samuel Johnson around the town on visits to his friends, and proudly have the young boy recite great passages of memorized scripture.