Origins of the Family, Private Property, and the State
- On line version of this key work by Engels.
- http://www.marxists.org/archive/marx/works/1884/origin-family/

Conditions of the Working-Class in England
- Fredrich Engel's widely read analysis of the effects of the industrial revolution on English life. An indictment of capitalism's oppression of workers in Victorian England.
- http://www.marxists.org/archive/marx/works/1845/condition-working-class/

Modern History Sourcebook: Engels: Industrial Manchester, 1844
- From Friedrich Engels, The Condition of the Working-Class in England in 1844.
- http://www.fordham.edu/halsall/mod/1844engels.html

Socialism: Utopian and Scientific
- Engels' most concise exposition of Marxism. Next to "The Communist Manifesto" this work is probably the most widely read introductory text on socialism.
- http://www.marxists.org/archive/marx/works/1880/soc-utop/index.htm

Marx/Engels Internet Archive
- Archive of Karl Marx and Fredrick Engels writings, speeches and letters
- http://www.marxists.org/archive/marx/index.htm