During WWII, many minorities, women, and other groups that don't have as much rights played a large role inside the military and it's influence, for example:
-Women: They worked inside factories to produce material for the army (as most of the men were out at war), as well as followed instructions placed by government (limits on certain produce). - African American: During WWII, the African Americans were able to serve inside the same regiments with other races, and were not discriminated as much military wise. - Minorities: Other minorities, such as the Native Americans, for example, knew that the war would affect them too. They also joined the US army even though they themselves were mistreated by the government, to prove that they too were part of the US.
Because of the large roles these people groups played, the US government and other citizens started to give them larger freedoms and rights, from civil rights to voting rights.
Islam spread through military conquest, trade, pilgrimage, and missionaries. Arab Muslim forces conquered vast territories and built imperial structures over time.