R.G. LeTourneau's last patent was granted on July 13, 1965, when he was 77 years old. In the 42 years between these two inventions he was granted 297 more patents and became one of the top inventors of all time.
These 299 inventions included the bulldozer, scrapers of all sorts, dredgers, portable cranes, rollers, dump wagons, bridge spans, logging equipment, mobile sea platforms for oil exploration, the electric wheel and many others.
LeTourneau built 70% of the heavy earthmoving equipment used by the allies in World War II. During the height of the war, from 1942 to 1945, his fertile mind pumped out 78 inventions, many of which were instrumental in helping to win the war.
Although LeTourneau had only a few years of formal education, his prodigious inventive efforts were recognized with dozens of industrial awards and he was presented with honorary doctorate degrees from five different colleges and universities.