How long would it take to plow 349 acres?

Historically, poorer men used a team of oxen as beasts of burden, but the man had to drive the oxen forward, walking behind to keep the team moving and keep the plow going in straight lines. A farm of 349 acres would not have been unusual-- many farmers had 100 to 400, or 400 to 1,000 acres in SW PA in the late 1790s. It could take many days to plow even a small farm of 20-50 acres, given the type of ground, the animals and man's stamina, whether the ground had been plowed before, etc.

As male heads of households prospered, they bought a horse or team of horses. The same techniques were used, with the man driving the animal(s) forward while the man stayed behind the plow. Horses were also beasts of burden and could work long hours. But it was still slow and tedious work.

Plow work broke many a man and their beasts (work animals).

Plows kept evolving, but still needed to be pulled and driven. Machinery greatly revolutionized farming. "Horse power" of a machine cut 1/4 to 1/2 of the work off a job. But machines needed tended even more than animals to keep the machine running. Farmers needed to know how to keep the motor in good order, or they had to go back to horses dragging the plow.