Starting in 1890, hundreds of Yemeni people from Hajz, Al-Baetha, and Taiz migrated to Aden to work at ports, and as labourers. This helped the population of Aden once again become predominantly Arab after, having been declared a free zone, it had become mostly foreigners. During World War II, Aden had increasing economic growth and became the second-busiest port in the world after New York City. After the rise of labour unions, a rift was apparent between the sectors of workers and the first signs of resistance to the occupation started in 1943. Muhammad Ali Luqman founded the first Arabic club and school in Aden, and was the first to start working towards a union.