PRESIDENTIAL TRIVIA, PART ONE

I'm slowly making my way through a giant book on every president, hoping to finish it while it's still up-to-date. Here are some interesting facts I've learned about our first 10 presidents. Post your guesses in comments and I'll post the answers there in a bit!
  1. 1.
    Here's the book in case any of you want to check it out.
  2. 2.
    And in case you don't have the first ten presidents memorized, here are your options for answers:
    George Washington, John Adams, Thomas Jefferson, James Madison, James Monroe, John Quincy Adams, Andrew Jackson, Martin Van Buren, William Henry Harrison, and John Tyler
  3. 3.
    Which of these presidents still has two living grandsons?
  4. 4.
    Which president was descended from England's King Edward III?
  5. 5.
    Which president was the first to be born an American citizen?
    Meaning he was born after 1776
  6. 6.
    Which 3 presidents all died on the 4th of July?
    2 on the exact same day, 1 in a different year
  7. 7.
    Who joined the Confederacy during the Civil War and became the only president to later become a sworn enemy of the US?
  8. 8.
    Which president's daughter was the first to get married in the White House?
  9. 9.
    How many of these 10 presidents had no higher education?
    Bonus points for naming them
  10. 10.
    Which president was first to be born under the US Constitution?
  11. 11.
    Which president liked to skinny dip in the Potomac?
  12. 12.
    Which president is still the only one for whom English was not his first language?
    Bonus points if you can guess what was his first language
  13. 13.
    Which president owned a pet alligator that he kept in the White House?
  14. 14.
    Which president was the first to shake hands in greeting instead of bowing?
  15. 15.
    Which president was related to George Washington?
  16. 16.
    Which president holds the title of shortest (height) president ever?
  17. 17.
    Which president is the only one to have a foreign-born First Lady?
  18. 18.
    Which president was the first to ride on a train?
  19. 19.
    Which president has fathered the most children (15)?
  20. 20.
    Which was the first president to ride on a steamboat?
  21. 21.
    Which was the first president to be photographed?
  22. 22.
    Which of these presidents died in office?
  23. 23.
    Which president's wife began the practice of playing "Hail to the Chief" to signal the president's arrival?
  24. 24.
    Which president delivered the longest inaugural address on record at 1 hour 40 minutes?
  25. 25.
    Which president delivered the shortest inaugural address at 135 words?
  26. 26.
    Who was the first president to marry while in office?