The president of the United States of America is one of the most powerful leaders in the world, presiding over the nation and wielding enormous influence around the globe. So when the president speaks, people listen. Words spoken by the nation's commander-in-chief can inspire us to achieve greatness (“We choose to go to the Moon … and do the other things, not because they are easy, but because they are hard” –JFK), steel us for the long road ahead (“these dead shall not have died in vain … this nation, under God, shall have a new birth of freedom” –Abraham Lincoln), comfort us in times of despair (“The only thing we have to fear is fear itself” –FDR). From George Washington (whose eloquent farewell speech taught us how to say goodbye) to Barack Obama (whose stirring refrain “Yes, we can!” set the positive tone for his presidency), U.S. presidents have had a lot to say. Here are great quotes from presidents of the United States.