Cyrus McCormick was an American inventor and businessman, the founder of the McCormick Harvesting Machine Company; born February 15, 1809 in Shenandoah Valley, Virginia, died May 13, 1884
Cryus McCormick's father originally had the idea, but McCormick took his idea over and built it in 1834 and soon after began manufacturing it himself
A reaper is a farm implement that cuts and gathers crops at harvest, making it much easier for farmers to do their jobs in the field.
Due to McCormick being born in Virginia, I presume that his father came up with the idea there, and McCormick himself initially developed it there.
The significance of the reaper is very important because it was a machine that made harvesting much easier and faster, for hundreds of years farmers and field workers had to harvest crops by hand, using a sickle, or other methods until the mechanical reaper. Throughout many years, the reaper had been changed by different people making it more advanced.