How did America’s role in the world change between the 1870s and 1910s

Technological innovation, economic growth, development of large-scale agriculture, and the expansion of the federal government characterized the era, as did the social tensions brought about by immigration, financial turmoil, federal Indian policy, and increasing demands for rights by workers, women, and minorities.

Explanation:

the main reason that the constitution did not proclaim all men to be free and equal is because of the issue of slavery.