Which US President had the most children?

President John Tyler, who served from 1841 to 1845, had 15 children between the years 1815 and 1860. He had them with two different wives. Eight were with his first wife, Lettia Tyler, and the other seven were with his second wife, Julia Gardiner. If you count the alleged child with a slave, that makes 16. He is the President with the most children.

William Henry Harrison with his wife Anna had ten and one with a slave making eleven.

Rutherford Hayes and his wife Lucy had eight children.

Franklin Roosevelt had six children with Eleanor.