Experience is a good teacher. During the American Revolution a smallpox outbreak threatened to wipe out the Continental Army as it had thousands of Native Americans. Despite political opposition, George Washington, the army’s commander in chief, embraced science-based medicine, ushering in the new country’s first public health policy.

Washington's initial move: immediately isolating anyone suspected of infection and limiting outside contact. He “prevented a disastrous epidemic among the Continental troops,” historian Ann Becker says. The military forbade anyone in Boston from entering the military zone. But Washington did more than that, Andrew Lawler writes for National Geographic . He moved to contain the threat.    Read more .