This feast was established in 1955 by Pope Pius XII as a response to May Day, but it is also a way to affirm the dignity of workers and work. One of the greatest saints in heaven was a humble carpenter! In the modern era, two forces seem to try to strip workers of their dignity: a Social Darwinist form of capitalism by degrading workers as wage slaves and nothing more than cogs in a Capitalist’s machine and Communism by despising the masses as ignorant and making them cogs in the state’s machine. Pope Leo XIII had already addressed this in an encyclical named Rerum Novarum (literally Latin for “Of New Things,” but Romans referred to revolutions by calling them new things; hence, the more accurate translation “Of Revolution”) on May 15, 1891. In this encyclical, he wrote about the rights of workers to fair conditions and wages and the rights of the rich to their property and personal safety. Pope Leo XIII basically paved a middle way between the two extremes. Though, the idea that the rich have certain obligations to the poor and that people have a right to their property have long roots in the Catholic Church. Leo XIII was basically just giving the modern world a summary of them.
Wishing you a happy Feast of St. Joseph the Worker!