Originally known as "Scott's Old Fields", Bel Air was part of a land grant issued to Daniel Scott in 1731. In March 1782 "Belle Aire" was designated the county seat of Harford County. At the turn of the twentieth century the "e" was dropped and the second "l" and its companion "e" gave way a few years later. The town's incorporation was effective in 1874. The town began with just 42 lots along Main Street centering on the Court House and the county jail and sheriff's house. Over the years, the population grew slowly to about 200 residents by 1865. The introduction of the canning industry, the Ma & Pa railroad and related financial businesses jump started the growth after the Civil War. Although the town experienced periods of rapid growth followed by extremely slow growth over the next century, Bel Air's role as the center of government and commerce continued to expand.