I learned about roads. This is information I found on a website http://xroads.virginia.edu/~hyper/detoc/transport/how.html "building a road involved simple technology and heavy labor. The first task, to clear the road, was usually the most difficult. Stumps, boulders, brush and trees had to be cleared. Usually, this was done entirely by hand or with the help of horses. It was not until the construction of the Erie Canal that an ingenious workman invented a stump-puller; using this device, seven men and a team of horses could pull forty stumps in a day."