Alachua, a county of Florida, in the N. part of the peninsula, bounded N. by the Santa Fe river and W. by the Suwanee; area, 1,000 sq. in.; pop. in 1870, 17,328, of whom 12,393 were colored. Orange lake lies partly within its limits. The surface is rolling prairie and the soil is fertile. The productions in 1870 were 168,580 bushels of corn, 8,450 of oats, 18.264 of potatoes, 2,477 bales of cotton, 58 hhds. of sugar, and 22,906 gallons Of molasses. The Florida railroad passes through the county. Capital, Gainesville.