<P> The McCormick Reaper was designed by Robert McCormick in Walnut Grove , Virginia . However , Robert became frustrated when he was unable to perfect his new device . His son Cyrus asked for permission to try to complete his father 's project . With permission granted , the McCormick Reaper was patented by his son Cyrus McCormick in 1837 as a horse - drawn farm implement to cut small grain crops . This McCormick reaper machine had several special elements : </P>
when was the reaper invented by cyrus mccormick
1837