Wildlife conservation, freeing the slaves, increasing military and defense funding, winning the liberating Cuba and the Philippines, etc.
They've generally expanded American interests while facilitating economic growth.
He was calm and collected in a time when we were on the brink of nuclear warfare. He made decisions that prevented such a catastrophe despite other top officials from suggestions to engage. He did this with a great deal of foresight. He also was integral in recognizing and pushing social issues that resounded around the country (civil rights).
Kennedy was the last president to cause as much fuss as Trump. Look what happened to him. Kennedy was a great political leader, no hatred only straight forward decisions best for all people regardless of beliefs.
They've generally expanded American interests while facilitating economic growth.