Early settlers depended on horses and horse drawn carriages for their transportation needs. However, horse drawn sleighs were essential to winter travel (and to recreation) in much of the country.
Transportation has been essential to the development of this country, in moving products and people. We have evolved from horse-drawn carriages to jets. Here you can see this evolution from saddles to the 1920 car.
Additional Sites:
Wagons on the Trails West - http://www.sover.net/~barback/ot/wagons.html
Horses Drawn Sleighs - http://www.astragalpress.com/astragal_horsedrawn.html
History of the Horse - http://www.wildheartranch.com/horses/horse_history.asp
Transportation technology - http://www.gsu.edu/other/timeline/trans.html