Explain how the American labor movement from 1870-1914 was a success or failure.

For most of this time, I would argue that the American
labor movement was a failure.  However, during the Progressive Era, the labor movement
can be seen as more of a success.

In the last decades of
the 19th century, the labor movement did not have much success.  Notably, the Haymarket
Riot of 1886 made labor look extremely bad and diminished its power considerably. 
Actions by employers and the government in such cases as the Homestead Strike of 1892
helped to further weaken unions.

With the coming of the
Progressive Era, however, unions started to make a comeback.  This can be seen, for
example, in Pres. Theodore Roosevelt's more even-handed policies towards strikes. 
Roosevelt even sent troops in to support workers in one strike, something that had never
been done before.  During the early 1900s, then, labor grew in
strength.

So, overall, I would say that the time period you
mention saw labor fail at first and then succeed.