The first seeds of socialism are planted on the banks of Indiana’s Wabash River – a utopian community designed by a social reformer who later inspired Karl Marx.

As Vladimir Lenin’s brutal communist revolution transforms Russia, socialism stalls in the United States.

Mao takes over China and socialism peaks worldwide - with 60 percent of mankind living under some form of it.

Poor countries embrace socialism with disastrous results, while Maggie Thatcher tells British socialists they’ve run out of other people’s money to spend.

The USSR implodes, China reforms and other countries embrace capitalism. It looks like mankind’s experiment with socialism is ending.

Despite a record marked by economic failure, political repression and countless lives lost, socialism makes a surprising comeback across the world – even in the United States, where Senator Bernie Sanders hopes to carry it into the White House.

Karl Marx said a workers' revolution was inevitable but by the end of the 19th century, it had failed to materialize. In response, some of his followers began developing an important strain of Marxist thought that would deeply affect America and the West.