The Knights of Labor began to organize workers in the second half of the 19th century. Their president Terence Powderly was Catholic as was two-thirds of the membership. In September, 1882, they staged the first "Labor Day" parade in New York City. In 1894 President Grover Cleveland declared Labor Day a national holiday.
The objective of the labor movement was the general welfare of all working people. Labor unions are responsible for most of the state and national labor laws, including child labor, working conditions, working hours and schedules (in Australia the holiday is called Eight-Hour-Day,) minimum wages, retirement plans and health care benefits.
Cardinal Gibbons of Baltimore went to Rome in 1886 to express his support for the Knights of Labor. Pope Leo XIII in 1891 published the encyclical "Concerning New Things." Not at all a liberal thinker he was wise enough to recognize that the abuses of workers demanded that the church take a position. Two of his main points were the right of workers to a living wage and their right to organize to protect their interests.