Unions were formed to advance the interests of the common workers against those of the owners of the companies in which they worked. This was pure Marxian theory where the workers (proletariat) were in constant class struggle with the owners of the companies (bourgeoisie).
Labor leader Samuel Gompers did not support communism or socialism. He believed in a free economy where labor unions would protect workers.
Daniel De Leon has written: 'The Socialist Trade and Labour Alliance versus the \\' -- subject(s): Socialism, Trade unions 'Woman's suffrage' -- subject(s): Suffrage, Women 'Revolutionary socialism in U. S. Congress' -- subject(s): Politics and government, Socialism 'A decadent Jeffersonian on the socialist gridiron' -- subject(s): Socialism 'Abolition of poverty' -- subject(s): Socialism and Christianity, Catholic Church 'Socialism versus anarchism' -- subject(s): Socialism, Anarchism 'Socialist landmarks' -- subject(s): History, Socialism, Trade-unions 'Fifteen questions asked by the Providence, R. I., \\' -- subject(s): Socialism and Christianity, Socialism, Catholic Church 'The burning question of trades unionism' -- subject(s): Labor unions, Political activity, Socialism, Socialist Labour Party (United States), Trade unions 'Anti-semitism' 'Writings of Daniel DeLeon' -- subject(s): Labor unions and communism, Socialism 'Reform or revolution' -- subject(s): Socialism, Socialist Labour Party (United States), Socialist Labour Party (United States). Section New York 'De Leon-Carmody debate' -- subject(s): Communism and individualism, Socialism, Socialist Labour Party (United States) 'Socialist vs. capitalist economics (Marx on Mallock)' -- subject(s): Marxian economics 'Socialism Versus Anarchism (Pamphlet)' 'Marx on Mallock' -- subject(s): Socialism 'Fifteen questions' -- subject(s): Socialism
Bryan D. Palmer has written: 'Labouring the Canadian Millennium' 'Cultures of Darkness' 'Canada's 1960s' 'E.P. Thompson' -- subject(s): Communism, Socialism, Dialectical materialism 'Work and unions in Canada' -- subject(s): Working class, Labor unions
I'm only guessing, but maybe Hitler associated organized labor unions with communism. He disliked communism. I would research this more. There must be much written about it.
The Solidarity Movement in Poland.
Unions, state health care, improved working conditions
Due to emergence of communism
Macroeconomics
Rune Nordin has written: 'Socialism' -- subject(s): History, Socialism 'Arbete och kamp' -- subject(s): Labor unions, Lumbermen, Woodworkers
Labor unions
Thomas Binning has written: 'Organized labour' -- subject(s): Labor unions, Socialism
David Joseph Saposs has written: 'Communism in American unions'