The United Steelworkers represent workers in a diverse range of industries, including primary and fabricated metals, paper, chemicals, glass, rubber, heavy-duty conveyor belting, tires, transportation, utilities, container industries, pharmaceuticals, call centers, museums, and health care.

The drive to create this union included such violent incidents as the infamous Memorial Day, 1937, when Chicago policemen supporting the rival American Federation of Labor (AFL) fired on workers outside a Republic Steel mill and killed 10 men.

[5] In April 2007, the USW also merged with the Independent Steelworkers Union, adding 1,150 members at Arcelor-Mittal's Weirton, West Virginia steel mill.

[9] Beyond its affiliations with other unions, in June 2006, the USW announced the formation of a 'Blue-Green Alliance' with the Sierra Club, with the goal of pursuing a joint public policy agenda.

[10] In October 2009, the USW announced a framework for collaboration between US and Canadian Steelworkers with Mondragon Internacional, S.A., the world's largest federation of worker cooperatives.

The unions have further announced that the new entity would target further mergers with labor groups in Australia and in the emerging economies of Asia, Latin America and Eastern Europe.

Based on these numbers, the United Steelworkers, in conjunction with the rest of the labor movement, took substantial credit for the eventual Democratic victory.

[20][21] USW International President David McCall stated in March 2024 that “Allowing one of our nation’s largest steel manufacturers to be purchased by a foreign-owned corporation leaves us vulnerable when it comes to meeting both our defense and critical infrastructure needs.”[22][21] The United Steelworkers was a founding partner of the New Democratic Party and continues to be an affiliated union.

The USW has enthusiastically supported The Institutes for the Achievement of Human Potential (IAHP), a nonprofit organization that works with brain-injured children.