@PotomacBobThe type of Farm, and the primary crop(s) matter quite a bit to determine an answer to your question.
A subsistence farm in Appalachia, New England, or the "Sod Busters" of the Great Plains would require the labor of one adult, or the entire family (typically of 6 to 12 adults and children). As mentioned elsewhere, this was typically around 40 acres; depending upon the quality of the soil, and the terrain.
New England soil was notorious for "growing rocks" (actually plowing the soil, combined with the freezing winters would result in rocks (from the size of a fist, to a large pumpkin) rising to the surface during the spring planting. Most of these rocks were used to build stone fences (more to do something about them requiring minimal effort. Resulting in smaller fields than most other regions of North America). We understand now (since c.1960's) why this occurred, but it was a mystery to folks in the 1600's to 1800's; many small farms were abandoned by folks heading West for better land.
(Poor) small farms were driven off of the fertile "Bottom Land" of Virgina (or the sandier soil of North Carolina) where they grew cash crops such as Tobacco. Rice, and then Cotton were the major cash crops in South Carolina and Alabama. Those poor farmers relocated into the Appalachians, where their airable land was broken up by steep slopes, and other terrain.
The Great Plains were arid, and until irrigation was used, most folk continued West to California, or Oregon (including what later became Washington state).
Subsistence farming was mostly vegetables, and tubers, in particular potatoes; potatoes and pumpkins were both discovered in the "New World" that quickly became staples of subsistence farmers in North America. Grains were also grown, both to make bread and porridge, and for animal feed. Chickens were common, and, if they could afford it, a couple of hogs (which could forage in the adjacent woods). A cow for milk, butter, and cheese, was an uncommon luxury. Mules or Oxen were more common than horses on the typical farm. However, it wasn't uncommon for at least one family in a community (or one amongst several nearby communities) to have a dairy, and another might breed horses. Mills, usually water powered, but possibly driven by oxen or a windmill, were common where grains were grown.
Grain has a number of likely problems. Storage of grain can be difficult, and there are numerous ways it can go bad, and it is vulnerable to rats and other pests. Grain is bulky and difficult to transport (even if ground into flour). This is why rural (western) New York, Pennsylvania, the Ohio valley, and other areas, often turned grains into Whiskey. Whiskey is much easier to store and to transport, and is worth more than the grain it comes from.
Flax was another crop that was commonly grown. Flax is a grain that may be eaten; it can also be used to make cloth.
Nearly all farms or Plantations that grew cash crops would also grow vegetables, and probably have chickens, and possibly hogs, a dairy cow, etc.
Roads were not efficient for the transportation of significant amounts of crops. Most plantations and large farms were near Ports on the Atlantic seaboard, or the Gulf of America (aka Gulf of Mexico). Navigable rivers, or canals (the Erie Canal was a major government project for commerce and to encourage Westward expansion) were the only practical means of transport for crops to Ports (all cities in the 1600's to early 1800's were ports).
Steam powered railroads c.1830 began expanding in the 1840's making the transportation of grain and other cash crops practical. Beef, dairy, and other foodstuffs began to be practical, instead or rare luxuries for the wealthy. {Citizens in the USA were considered wealthy by most people in Europe because of their luxurious diet, including meat. Americans c.1770 to 1840 were 4" or more taller and healthier than an average Englishman, and even more so than a Frenchman.)
McCormick Reapers and other horse (more other mule or oxen) drawn farm equipment allowed one man to harvest as much grain as a dozen men could. Seasonal laborers were hired to harvest crops. They would start in the north and work their way down south (regionally. In "Dixie" it was more common for slaves to be allowed to earn some money by working on other farms if everything was taken care of on their plantation; their owner would "of course" get a portion of their wages.)