Why couldn’t African-Americans or poor White farmers start their own farms?

Although the tenant/sharecropping system is usually thought of as a development that occurred after the Civil War, this type of farming existed in antebellum Mississippi, especially in the areas of the state with few slaves or plantations, such as northeast Mississippi.

Not all whites who emigrated to even the poorest parts of Mississippi in the years before the Civil War had the funds to purchase a farm. As a result, most of the men who headed these households worked as tenant farmers or sharecroppers. Many rented land from or farmed on shares with family members and typically received favorable arrangements, but some antebellum tenants or sharecroppers had to deal with landlords who were primarily concerned with making profits rather than helping struggling farmers move toward landownership.

Consider the sharecropping arrangement that Richard Bridges of Marshall County worked out with his landlord, T. L. Treadwell, in the 1850s. Treadwell provided Bridges with land, livestock, and tools; the landlord also advanced Bridges some food. Bridges grew corn and cotton, and at the end of the year, he had to give Treadwell one-sixth of the corn he grew and five-sixths of the cotton raised. From his share of the crop, Bridges also had to pay Treadwell for the use of the livestock and tools and for the food advanced. Obviously, Bridges worked the entire year primarily for the food he needed to live. He had no opportunity to make any money from this arrangement and accumulate the capital that would allow him to purchase his own farm.

Very useful. it is to learn because history repeats itself so learning about it those mistakes not happen again.