For Labor Day, we’re going way back to the 1930s, during the construction of New York City’s RCA Building, better known today as 30 Rockefeller Plaza, or simply ‘30 Rock.’ While many of us will spend the weekend grilling, working, or maybe even napping like these workers (hopefully not 800 feet above the ground, though), it’s worth noting the origins of this holiday. Labor Day was established in the late 19th century, by trade unionists who proposed a day to honor the contributions of the labor movement. However you labor, and however you spend your day, we hope it’s a pleasant one.