Lyric discussion by Kiwimartin 

Cover art for Chicago lyrics by Crosby, Stills, Nash & Young

Fotunately no one was killed during the police riot outside the Democratic Party National Convention at Chicago in 1969 but many were injured and arrested.

The 'brother' who was ''bound and gagged and chain to a chair" was Black Panther leader Bobby Seale. This was during the trials held later.

When this is sung in concert they usually sing 'Throw them out the door" instead of "Open up the door". It seems to make more sense and the recorded version was probably to appease the record company.