You're right. It's 3.

The second, the third and the fifth US presidents died on Independence Day. On the 4th of July, 1826 Thomas Jefferson and John Adams, who were once fellow Patriots and then adversaries, died within five hours of each other. The fifth US president James Monroe died on the 4th of July, 1831. Jefferson died from a kidney infection, Adams died of heart failure and Monroe passed away a result of tuberculosis.

More Info: