Inventor of the Horse-Drawn Reaper,
[Pennsylvania Genealogies, by William Henry Egle published in 1896:]
Robert McCormick (June 8, 1780 - July 4, 1846) was an American inventor, who invented numerous devices including a version of the reaper which his eldest son Cyrus would patent in 1834.
McCormick was born on the family estate of Walnut Grove in Rockbridge County, Virginia, in the Shenandoah Valley on the western side of the Blue Ridge Mountains. He married Mary Ann Grigsby in 1808 and was granted ownership of Walnut Grove in 1810. Robert and Mary Ann raised their eight children on the farm there and the kids grew up helping in the shop and the mill. Robert frequently busied himself with small gadgets and inventions around the farm.
By 1809, Robert had constructed a partially completed reaper. He eventually decided to formalize some of his work when he applied for a patent in 1830 for a "hemp-break", a device for breaking hemp and flax. He also produced a threshing machine, a clover sheller of stone, a blacksmiths bellows and a hill-side plow. By 1831, he had completed a reaper. He was encouraged by Polly to give it to their assertive and business-minded son Cyrus, who was able to improve and patent it in 1834.
In addition to Cyrus, his sons included Leander J. McCormick and William Sanderson McCormick. These three brothers moved to Chicago after their fathers death, and established the McCormick Harvesting Machine Company. In 2002, Robert and his three sons had a variety of wheat named after them, for "inventing, perfecting, manufacturing, and marketing of the mechanical grain reaper [which] ushered in the era of modern agriculture and wrought one of the greatest advancements in agricultural history.McCormick is a soft red winter wheat (Triticum aestivum L.) developed and released in May 2002 by the Virginia Agricultural Experiment Station.
Roberts grandson, William Grigsby McCormick is one of the founding fathers of the Kappa Sigma Fraternity. [Wikipedia2008] from:
The McCormick reaper legend; the true story of a great invention, by Norbert Lyons, New York, Exposition Press 
Memorial of Robert McCormick, Life, Character and Inventions, Chicago, Barnard & Gunthorp, 1885, (Google) p.1ff,
Dau. of Patrick HALL and Susan McCHESNEY [Memorial of Robert McCormick, 1885, p.1: b. near Harrisburg in 1738.]
1.+Cyrus Hall McCORMICK, b.15 Feb.1809 Walnut Grove, Rockbridge Co., VA,
2. Robert Hall McCORMICK, b.24 May 1810, d.29 June 1826 Rockbridge County, VA,
3. Susan J. McCORMICK, b.1 Aug.1813,
4.+William Sanderson MCCORMICK b: 2 Nov1815 Walnut Grove, Rockbridge Co., VA,
5.+Mary Caroline McCORMICK, b.18 Apr.1817,
6.+Leander James McCORMICK, b.8 Feb.1819,
7. John Prestly McCORMICK, b.8 Nov.1820,
8.+Amanda Joanna McCORMICK, b.17 Sep.1822,