Mohawks came from Kahnawake and other reserves to work in the construction industry in New York City in the early through the mid-20th century. They had also worked in construction in Quebec. The men were ironworkers who helped build bridges and skyscrapers, and who were called skywalkers because of their seeming fearlessness. They worked from the 1930s to the 1970s on special labor contracts as specialists and participated in building the Empire State Building. The construction companies found that the Mohawk ironworkers did not fear heights or dangerous conditions. Their contracts offered lower than average wages to the First Nations people and limited labor union membership. About 10% of all ironworkers in the US are Mohawks, down from about 15% earlier in the 20th century.