The United States is, by far, the largest producer of corn in the world, producing 32 percent of the world's corn crop in the early 2010s. Corn is grown on over 400,000 U.S. farms. The U.S. exports about 20 percent of the U.S. farmer's corn production. Corn grown for grain accounts for almost one quarter of the harvested crop acres in this country. Corn grown for silage accounts for about two percent of the total harvested cropland or about 6 million acres. The amount of land dedicated to corn silage production varies based on growing conditions. In years that produce weather unfavorable to high corn grain yields, corn can be "salvaged" by harvesting the entire plant as silage. Additionally, corn farming has become exponentially more efficient. If U.S. farmers in 1931 wanted to equivalently yield the same amount of corn as farmers in 2008, the 1931 farmers would need an additional 490 million acres.
The largest grain farm is based out of Gettysburg S.D.
There are several large row crop farms in the US. The largest seems to be the Battle Farms of Tunica.
In terms of sheer volume, the largest crop by far is corn or maize.
The largest farm is 65,000 acres.
California.
Corn is their largest crop, but they are far from being the largest corn producer. They are the largest producer in the US of barley.
The largest poultry farm in the US is the Tysonchicken farm. The Tyson chicken farm is located in Springdale, Arkansas.
The Fair Oaks Farm is the largest dairy farm in USA. It is situated between Indiana and Illinois.
This question seems to speak about US history. In the South, most crop workers were slaves. In the North, farmlands were worked by farm owners and their paid farm workers.
California.
US farm cooperatives help their farmer members by getting large volume pricing on crop inputs such as seed, fertilizers, crop protection chemicals, and sometimes specialized farm implements. They also sometimes provide a common location for delivery, storage, and/or transportation of the crop after harvest.
State Farm
state farm
Nebraska, Oklahoma, and Missouri produce most of the grain sorghum grown in this country.
In this case, the word "head" is an abbreviation for header. A header is the implement mounted to the front of a combine harvester to reap and gather the crop for threshing in the middle part of the machine. A row crop header is a header designed specifically for harvesting crops which are planted in individual rows. In the midwestern US, this is typically corn. A row crop header for harvesting corn can be seen in the related link below. I just randomly picked one brand of combine harvester -- no implication pro or con to the brand.