in 1862 the united states congress passed the homestead act which led to the settlement of a large part of the midwest. the united states also witnessed a great increase in railways, mainly across the prairies. in 1860 the united states possessed about 30,800 miles of railways; by 1880 this had increased to about 94,200 miles. the railway companies encouraged farmer-settlers by promising to transport their crops for less than cost for a number of years. due to the technological progress of shipping, there was for the first time plenty of cheap steam ships to transport their crops across the seas. this drove down transport costs: in 1873 the cost of transporting a ton of grain from chicago to liverpool was £37"s"., in 1880 it was £21"s". and in 1884 £14"s". new inventions in agricultural machinery also aided the american prairie farmer. due to the scarcity of hired farm labourers, prairie farmers had to collect their own harvest and the limit of their expansion was set by what one pair of hands could do. the advent of the reaper-binder in 1873 revolutionised harvesting because it meant the doubling of every farmer's crop as it enabled the reaping to be worked by one man instead of two. for these reasons, cheap imports of vast amounts of american prairie wheat were able to flood the market and undercut and overwhelm british wheat farmers.