Steam locomotives, originally designed in England, were first tested in America in the 1820s. Steam locomotives pulled freight trains for the first 130 years of the industry before giving way to diesel locomotives (a.k.a. diesel electrics) in the late 1930s and early '40s. The U.S. freight industry experimented with electric locomotives for freight trains beginning in the late 1870s. These locomotives found little popularity in the American freight industry but are now often used for public transportation.
Over a dozen types of freight cars exist. The first freight trains primarily moved goods on flat cars and gondola cars (cars with short railings on the side). House cars, later known as boxcars, came about in the 1930s and became a staple on freight trains for their versatility. Other common types include tank cars containing liquids and hopper cars for hauling coal and ore.
Coal represented nearly half of freight train tonnage in 2002. Other common goods shipped by freight trains include steel, industrial chemicals and agricultural products.
2002 witnessed 554 freight lines shipping goods in the United States. The top grossing railroads included Burlington-Northern and Santa Fe, CSX Transportation, Kansas City Southern and Union Pacific.
The Federal Railroad Administration launched Operation Lifesaver in 1972, a year that included 12,000 collisions between trains and motor vehicles. Accidents between trains and motor vehicles declined sharply between 1972 and 2009, when a total of 1,900 crashes occurred, resulting in an 84% decrease.
