He relocated to an area known as McNeil's Mill and leased land along a creek in Autauga County in 1836, where he began manufacturing cotton gins.

As his business grew, he branched out with a sawmill, gristmill, window factory, iron foundry, woollen mill, railroad, bank, and the Oxmoor Blast Furnace in Birmingham.

Pratt's businesses were badly affected by the American Civil War; many of his workers joined the military and his customer base shrank as the economy soured.

His ability to call in debts on Northern accounts allowed him to rebuild his own operations, which helped make Autauga County exceptionally stable and prosperous in the period immediately after the Civil War.

One of Pratt's slaves, Charles Atwood, purchased a house in the center of Prattville immediately after emancipation and became one of the founding investors in his former master's railroad ventures.