640 Acres
I'm not sure what you mean by a "section" of land, but in rural areas or for large properties, land is measured by the acre in the U.S. In urban and suburban areas, lots (plots of home on which a house sits) are usually measured in feet. For example, my house is in a town with old-fashioned narrow, deep lots. My lot measures 50 feet (wide) by 200 feet (deep). You can convert feet to acres and vice versa using any of the online conversion sites.