Marxist feminism, as with all Marxist theories, bases all the blames of feminism on the system of capitalism. According to Wikipedia and Marxist idealists, capitalism is the root of women's oppression because of the fact that it "gives rise to economic inequality, dependence, political confusion and ultimately unhealthy social relations between men and women." Marxist feminists believe that by eliminating the capitalist style of American society women's oppression would be removed. According to Marxist theories any type of oppression is wrong.
Personally, I do not agree with any of Karl Marx's theories. Marxism should be called what it really is, and that is communism. Many people consider Marx one of the leaders who brought about communism with his ideas and writings. Communism is the government of such countries as North Korea and China, where the government basically runs your life and everything that you can do. That is why Marxist feminism seems to work, because with communism everyone except for the leaders are equal to the rest. Except to have Marxist feminism you must have a communist type of government that will enforce those beliefs and that is where my disagreement comes.
Karl Marx is obviously the most influential person in the creation of Marxist feminism. The biggest group of people that practice Marxist feminism are called "Radical Women," they consist of the largest group of supporters. Some websites that I found explaining Marxist feminism are the Wikipedia page found here: http://en.wikipedia.org/wiki/Marxist_feminism, also this page has some good information on it: http://www.feministissues.com/marxist.html.