Comparing 1(revised)

Compared to these two men, John Adams and Thomas Jefferson, the greatest persons in the U.S history, they have many differenances.  First, both of them played an important role in American Revolution.  Second,  they delegated to the Continental Congress and studied or practiced law as well.  Next, Jonh Adams was a signer of Declaration of Independence and so was Thomas Jefferson.  Moreover, the date they died was the same-July 4,1826.
These two people are alike in many ways, perhaps there are something meaningful behind these coincidence.