<P> The geographic center of the contiguous United States is the center of 48 U.S. states . It has been regarded as such by the U.S. National Geodetic Survey (NGS) since the 1912 additions of New Mexico and Arizona to the United States . </P> <P> Its position as located in a 1918 survey is located at 39 ° 50 ′ N 98 ° 35 ′ W ﻿ / ﻿ 39.833 ° N 98.583 ° W ﻿ / 39.833; - 98.583 ﻿ (Geographic Center of the Contiguous United States), in Kansas about 2.6 miles (4.2 km) northwest of the center of Lebanon, approximately 12 miles (19 km) south of the Kansas - Nebraska border . </P>

Where is the exact middle of the united states