At the beginning of the 20th century, Monrovia was divided into two parts: (1) Monrovia proper, where the city's Americo-Liberian population resided and was reminiscent of the Southern United States in architecture; and (2) Krutown, which was mainly inhabited by ethnic Krus but also Bassas, Grebos and other ethnicities. Of the 4,000 residents, 2,500 were Americo-Liberian. By 1926, ethnic groups from Liberia's interior began migrating to Monrovia in search of jobs. The population of Monrovia reached 10,000 by 1937; at that time, Monrovia's police department had 30 members.