Jefferson raised tobacco for sale to European markets until the early 1790s. Then, market forces and an interest in agricultural reform led him to institute a more diversified operation, with wheat as the main crop. The new system involved a greater variety of tasks, which gave enslaved workers additional skills and increased autonomy, enabling them to negotiate small improvements in conditions for their families.
Stacking Wheat, Culpeper, Virginia, 1863. Courtesy Library of Congress