Unions during the late 19th century did not enjoy great success or growth mainly because
It was due to the Sherman Anti-trust Bill. Under this bill, joining unions was illegal. Strangely this bill was created to prevent
the abuse of big business but it managed to prevent workers from creating or
joining unions at the time.
The correct answer is "there was a great diversity of skill and cultures in the labor force, so there was little bargaining power to be won by unions"