1. from alternative spelling of canvas (n.) and probably meaning, originally, "to toss or sift in a canvas sheet," hence "to shake out, examine carefully" (1520s); "to solicit votes" (1550s).
2. canvas => canvass => canvasser.

1. Here was a type of the travelling canvasser for a manufacturing house -- a class which at that time was first being dubbed by the slang of the day " drummers.

”这人是为生产厂家 推销 产品的旅行推销员,当时刚刚流行把这类人称作“皮包客. ”

来自《简明英汉词典》

2. It'seems the canvasser was once a general.

那位推销员好像原来是一位将军.

来自互联网