Which factor produced gains in union membership in the united states during the late 19th century and early 20th century? the encouragement factory owners gave to organized labor the increased efforts of the federal government to break up monopolies the beginning of widespread outsourcing of american jobs to foreign countries the shift from an agricultural economy to an industrial economy

The answer is: the shift from an agricultural economy to an industrial economy

At that time, the confederates rely on agricultural sectors as the largest source of income while the union states rely on manufacturing supported by technological invention as their main source of income.

As the economy shifted from agricultural economy to an industrial economy, more states become more reliant to the union states. This influence them to join the union memberships in the late 19th century and early 20th century.