The Grumman-Olson company was the pioneer of the "walk-in" van. Grumman, the aircraft manufacturer, planned on building the trucks in 1939, but WWII interrupted production. The company became famous for the Kurb Van and LLV models, which are still in use today by companies like UPS and the U.S. postal service. The company changed hands several times before going bankrupt in 2001. Today, the trucks are still built under the name Morgan Olson.