In 1918, it became the first labor union to win the legal right to represent federal workers.
The union does not represent workers in the computer unit.
Currently, a union must win the right to represent a company's workers in a special election.
The union represents 126,000 workers, more than a third of the municipal work force.
It also represents workers in a number of other industries.
It was founded before the turn of the 20th century, and represents 230,000 workers.
His union represents the Plaza's 900 workers, who stand to lose their jobs.
Local 237 represents 11,000 workers, including security officers at hospitals and schools.
Fewer than half of the companies involved had employed workers represented by a union.
"We needed some way to represent workers who are not connected to the workplace."