pitch in and help

pitch in (and help)

in. to volunteer to help; to join in completing a task. If more people would pitch in and help, we could get this job done in no time at all.
See also: and, help, pitch
References in classic literature ?
You know the saloon is one of them patent houses you can take to pieces, and I've been reckoning you boys will have to pitch in and help me to take the whole shanty over to the laurel bushes, and put it up agin Kearney's cabin.