In the late 1800s and early 1900s, reformers immigrants assimilate into american culture by

teaching them to speak English.

The reformers who wanted to help immigrants assimilate and succeed in American culture knew that learning English was key to their success in American economy and way of life. Americanization efforts also included instruction in US history and the way democracy works in the United States.

they gained popular support by speaking out against communists

in the united states. ( d.)

this isn't a question and if you're going to list things be kind and use commas.