The beginning of practical efforts in the direction of harvesting by wholly mechanical means may be said to date from the beginning of the last century, about the year 1800, although very little progress was made from that time up to the year 1831.

Near the close of the past century, the subject of grain-reaping machines again began to claim the attention of inventors. American invention in this line, so far as there is any record, began with the patent issued to Richard French and T. J. Hawkins of New Jersey, May 17,1803.

In a letter written by the son of the inventor, he says that his father constructed a working machine, and tried it in a field of rye, and that it cut a large quantity of the grain. The reaper was supported on the wheels — one wheel extending into the grain. The horses drew in front, or rather at one side, opposite the cutters, which were a series of scythe-knives, revolving on a vertical spindle — a rotary reaper. Beneath the cutters were long wooden fingers, extending some distance into the grain, and supporting the grain to the action of the revolving cutters. Directly behind the cutters were fingers that passed between the cradle fingers, and removed the cut grain, which fell to the ground ready for binding.

According to wikipedia