This article has a few entertaining excerpts:

"In the 1770s a party-hearty type named Collins led a team that surveyed the boundary between Quebec and Vermont. On one 22-mile stretch, a fifth of their expenses went for booze. The result, an international commission later acknowledged, was 'very far from a straight line.' "

"Magnetic compasses don't point to the north pole, but rather to a spot about 500 miles distant, a fact surveyors take into account when determining true north. This subtlety was lost on some early surveyors. The knuckleheads who laid out most of the Virginia-North Carolina-Kentucky-Tennessee border didn't realize they needed to adjust their adjustments, so as they headed west, the boundary curved north. The surveyors who handled the western end of the border, working east from the Mississippi, covered less ground and so had less chance to screw things up. Where the two lines meet, at the Tennessee River, there's a 12-mile jog still conspicuous on maps."

http://www.straightdope.com/columns/read/2907/how-did-the-states-establish-long-straight-borders-before-gps