What military persons am I describing?

Question

1. I led my men on a surprise attack on the Hessians. We had to cross a river to get to them.
2. One of my greatest victories was "The Seven Days Battle."
3. I represented my country in the 1912 Olympics,in the first Modern Pentathlon. ( an obscure but interesting clue.)
4. I was defeated at Yorktown.
5. Although I lost my left arm, I was considered Lee's "right arm."
6. I was the 12th chairman of the Joint Chiefs of Staff, and the youngest.

Answer 1

1 George Washington
2 Robert E. Lee
3) George S Patton (Had to look this one up)
4) Lord Cornwallis
5) Stonewall Jackson
6) Colin Powell (Had to look this one up)