The NYT reviews the new book Measuring America:

Jefferson, Washington, Madison and Hamilton wanted the mapping done by decimal measurement. The flood of settlers and speculators already spilling westward meant that there was no time to work out the new and still disputed system. Measurement would be made by a device already in use for some 150 years: the surveyor's chain, 66 feet long and 80 chains to the mile.

http://www.nytimes.com/2002/12/26/books/26EDER.html