You've picked on a vast and sprawling subject which I couldn't possible tackle in one posting. For discussions of labour songs (rather than anthologies) take a look at John Greenway's American Folksongs of protest. ISBN 0374932549. It's an old book and one written by an anthropologist rather than a folkl song specialist. But it's still the best work on its subject.
Also, Only a Miner, by Archie Green and Pistol Packin' Mama: Aunt Molly Jackson and the Politics of Folksong by Shelly Romalis. Both of these deal with songs in the American coal industry.

Recommendable song collections include;

Joanna Colcord: Songs of American Sailormen. Oak Publications, New York, 1964
William Doerflinger. Shantymen and Shantyboys: Songs of the Sailor and the Lumbermen. Macmillan Co., New York, 1951.
Stan Hugill: Shanties from the Seven Seas. Routledge & Kegan Paul, London, 1961.
Hard Hitting Songs For Hard Hit People, edited by Alan Lomax with assistance from Woody Guthrie And Pete Seeger is still probably the best source of American labour protest songs ever compiled.
John Lomax. Cowboy Songs and other Frontier Ballads.
The Long Steel Rail. Norman Cohen

For sound recordings, there are numerous anthologies of cowboy songs, but the best is probably a double CD called Back in the Saddle Again. New World. NW 314/315-2.

Also, try Virginia Work Songs on Global Village CD1007. These are archive recordings with, as I recall quite a lot of prison worksongs. However, it also includes several shanties collected among fishermen of the Virginia coast.

American Sea Songs and Shanties, Rounder 18964-1519-2, is pretty well unique in that it documents shanties which were collected from genuine sailing ship shanty singers.

Tipple, Loom and Rail is an old Folkways LP of American industrial songs by Mike Seeger. I've never heard it, but would imagine it to be indispnsable to your quest. It's long been out of catalogue, but you should be able to download it from the Smithsonian Folkways site at http://www.folkways.si.edu/index.html.

Finally, just about any release featuring Woody Guthrie will have masses of relevant songs. I'd particularly recommend the Library of Congress Recordings set, if it is still available.

As I said, it's a huge subject, and that lot doesn't even begin to scratch the surface. But it might point you in a few directions.

Cheers,

Fred McCormick.