The measurement known as a mile is a vestige of the Roman Empire's rule over Britain. At this time, the Romans had a measurement known as mille pasuum (ME-lay PA-soo-em), or a thousand paces. A pace comprised five, possibly sandal shod, Roman feet. Using a simple mathematical calculation, we arrive at 5,000 feet per mile.
The demise of the Roman Empire left the Britons in a quandary. They now had a mile, consisting of 5,000 feet, and their own agricultural measurement, the furlong, used to measure the farmers' fields for the purpose of property deeds, etc. Instead of using the Roman foot in calculating the measure of a furlong, they used the distance a horse could pull a plow, in a linear fashion, before the nag needed a nap. They agreed that this measurement consisted 660 feet.
Now came the dilemma. The British wished to marry the furlong to the mile, but, as they wanted a mile to comprise eight furlongs, totaling 5,280 feet, instead of the Roman 5,000 feet per mile, they had no choice but to select one of the two. Not surprisingly, they chose their measurement over the Roman measurement because, as property deeds at the time were measured in furlongs, or 660 feet, a change to the Roman measurement would short the farmer or landowner.