<Tr> <Td> Printing </Td> <Td> 20 </Td> <Td> Liquor </Td> <Td> 44 </Td> <Td> Meatpacking </Td> <Td> 124 </Td> <Td> Clothing </Td> <Td> 239 </Td> </Tr> <Tr> <Td_colspan="8"> Source: Joel Mokyr </Td> </Tr> <P> Railroads saw their greatest growth in new track added in the last three decades of the 19th century . (See Table 2) Railroads also enjoyed high productivity growth during this time, mainly because of the introduction of new processes that made steel inexpensive . Steel rails lasted roughly ten times longer than iron rails . Steel rails, which became heavier as steel prices fell, enabled heavier, more powerful locomotives that could pull longer trains . Rail cars made of steel on steel roads could be made longer cars and had a load carrying to car weight ratio of 2: 1 compared to cars made of iron at 1: 1 . </P> <P> In 1890 David Ames Wells estimated wagon transport at 16 cents per ton - mile compared to railroads at less than one cent per ton - mile . </P>

Which part of the u.s economy had the biggest boost after world war 1