Source A: Excerpt from a labor union pamphlet (1912)

'Labor unions are essential to securing fair wages, safe working conditions, and reasonable hours for workers. They organize strikes and negotiations to stand up against exploitation by factory owners.'

Provenance: Published by the American Federation of Labor, 1912.

Source B: Summary of the Pullman Strike (1894)

'The Pullman Strike was a nationwide railroad strike that disrupted rail traffic and mail delivery. It was led by the American Railway Union and protested wage cuts and high living costs in Pullman company housing.'

Provenance: Historical summary from a textbook, 2000.

Source C: Excerpt from a newspaper article (1913)

'Labor unions face opposition from factory owners, government, and sometimes even from within their own ranks. Laws have been enacted to limit their power, and strikes are often broken up by force.'

Provenance: The New York Times, 1913.

Source D: Historical opinion (1930s)

'The efforts of labor unions during the Progressive Era laid the groundwork for future labor laws and workers' protections. Their activism helped shape modern labor rights.'

Provenance: Historian's analysis, 1930s.