What is a foot?
The foot is an imperial and US unit of length equal to 12 inches, or exactly 30.48 centimeters. It is a third of a yard and 1/5,280 of a mile.
The foot began as the length of a human foot, and so differed from place to place and from person to person. The modern international foot was fixed at exactly 0.3048 meters by agreement in 1959.
People's height is given in feet and inches in the US and UK, and aircraft altitude is given in feet nearly everywhere, metric countries included.
What is a US league?
A US league is three miles or 15,840 feet. The word comes from the Late Latin leuca, a Gaulish measure traditionally taken as an hour's walk.
The league was used for the distance between towns and for a ship's run at sea. The mile and the kilometer replaced it, and it now mostly turns up in older books. A US league of three miles is about 4.83km.