Alpharetta is a city in Fulton County, Georgia, United States. Selected for its location next to a spring, it began as a campground, and was originally known as New Prospect Camp Ground until late 1858. Officially chartered on December 11 of that year, Alpharetta ( Greek for "first town") became the county seat of Milton County until the end of 1931, when Milton was merged with Fulton County to avoid bankruptcy during the Great Depression. Alpharetta is located 14 miles north of Atlanta’s central business district and 28 expressway-miles from Hartsfield-Jackson Atlanta International Airport, the world's busiest airport. Georgia 400 (U.S. 19) is the freeway connecting suburban Alpharetta with Atlanta to the south. It parallels surface highway S.R. 9, which was originally multiplexed with U.S. 19 and was the only paved road through town prior to the county merger. The town also had no railroad, a rarity for the area. Despite its poor start, and being one of the farthest-out large suburbs in metro Atlanta, it now features numerous mid-rise buildings, which are home to many high-tech companies including Hewlett-Packard, UPS Supply Chain Solutions, Radiant Systems, NetBank, Lucent, Nortel, IBM, Sun Microsystems, AT&T, Siemens, Verizon, Verizon Wireless, Alltel, E*Trade, Hansgrohe, and ChoicePoint.