John McCain, a titan in the U.S. Senate, was a consistent conservative, though unafraid to buck Republican Party leadership on issues ranging from campaign finance reform to the GOP-led effort to repeal the Affordable Care Act.
While the Arizona senator and two-time presidential candidate will be remembered for his self-proclaimed "maverick" persona, it was his military bloodlines and 5.5 years as a prisoner of war in Vietnam that shaped much of McCain's legacy.