Original: First Lady of the United States She is now considered to have been First Lady of the United States from March 4, 1801 to March 3, 1809 because her father was a widower, making her the first First Lady not to be a wife of the president.
Simplified: Because her father was a widower, Martha Washington Jefferson Randolph was considered the First Lady of the United States from March 4, 1801 to March 3, 1809.