During the industrial revolution in the United States, labor organizations such as the National Trades' Union, National Labor Union and Knights of Labor endorsed the development of democratic worker-controlled enterprise as a strategy for fighting “wage slavery” and developing a democratic economy. A stated goal of the Knights of Labor was “to establish cooperative institutions such as will tend to supersede the wage-system, by the introduction of a cooperative industrial system.” However, the creation of democratic worker cooperatives in a capitalist context proved exceedingly difficult. Capitalists attacked union co-ops, sometimes violently, but most often denied investment capital and limited access to markets. Repeated co-op failures, conservative labor leaders' acceptance of capitalist control over production, and the Marxist—Leninist emphasis on state control as the only means to power led labor to drop worker cooperative development as an organizing strategy. Now, at the beginning of the 21st century, diverse social movements around the world are showing a renewed interest in organizing democratic workplaces. Promoting democratic work is a key tenet of the solidarity economy movement that seeks to build an economy based on democracy and mutual support from the ground up. Solidarity economy activists argue that instead of waiting for an apocalyptic revolution, it is necessary to start building the new society in the context of old one.