The correct answer is The American Communist Party.
Communism is a government system in which the government controls all the means of productions and resources, in hopes of achieving economic equality among all citizens. This ideology became prevelant on a global scale thanks to the Bolshevik Revolution in Russia. In the US, after World War I, there was a small communist party that was hoping to bring radical change to the US. Ultimately, this party helped lead to the first Red Scare. This was a time of increased paranoia and fear of communism within the US government.