1. President’s who changed the Role of Presidency
The following is a list of Presidents and the events they were involved with that changes the role of the President and their Constitutional powers.

2. Thomas Jefferson
Jefferson purchase of the Louisiana Territory greatly expanded the role of the President. He was the first President to take bold steps to beyond the defined role of the President in the Constitution.

3. Andrew Jackson
Andrew Jackson disregarder the Chief Justice of the Supreme Court, John Marshall’s decision to protect the rights and property of the Cherokee. Jackson passed the Indian Removal Act of 1830 and pushed the Native American’s past Oklahoma and the Missouri River

4. Abraham Lincoln
Abraham Lincoln further broadened the power of the President with the decisions he faced during the Civil War, specifically the Emancipation Proclamation which stated that slavery was illegal in the all northern states.

5. Harry Truman
Harry Truman’s decision to drop the first and only weapon of mass destruction on Japan was a commander in chief decision that is unprecedented. It was undoubtedly one of the most far reaching and tough decisions a President has ever made.

6. Franklin Roosevelt
Roosevelt's decisions during the 1930’s further expanded the President decision making. He had to make many tough decisions about during the Crash of the Stock Market, like closing Banks so Banks would not go broke, Roosevelt’s decisions were by far the broadest expansion of Presidential power. With WW2 following the Great depression his leadership was instrumental.

7. Lyndon Johnson
Lyndon Johnson had to push through legislation called the Tonkin Resolution which allowed the US to send troops in the most controversial war this country had been in to date, the Vietnam War. The war ended up being a political nightmare for Congress and President Johnson.

8. George Bush Jr.
Bush’s decision after 911, encompassed with the situation with Saddam Husain not only created ground-breaking decisions as President but also created a lot of controversy as to whether this nation should do those kind of things.