Setling the Great Plains (from After the Civil War)

immigrants

people who come into a country to live

lately

recently; not long ago

transport

move goods or people by a vehicle, such as a train

cowmen

farmers who raise cattle

transcontinental railroad

a rail line reaching across the nation

crews

groups of workers

spike

a large, strong nail

Great Plains

a dry, treeless area in the middle of the United States.