how were theodore and franklin related
Yes. In relation to Theodore, Franklin Roosevelt was a distant cousin who later become a nephew-in-law, when he married Teddy's niece, Anna Eleanor Roosevelt. Franklin and Theodore Roosevelt were both descendants from Dutch colonists, who settled in the New York area in the mid-17th century. According to any Franklin Roosevelt biography, the two were fifth cousins, having a paternal relative in common (Nicholas Roosevelt, 1658-1742).