The Seventeenth Amendment was accepted by the Senate in 1912 and ratified in 1913. The main reason for the amendment was the progressive movement for greater public participation in the political process. It authorized the popular election of senators and was only accepted after four attempts (every attempt was denied for the so-called "millionaires" club, the Senate at that time).
A slave is a person that belongs to another one and is treated as property. Serfs, I'm not so sure about this now, were renting the land out from the landowners.
Homo Erectus was the first hominid to stand upright
negotiating with employers
Strikes
