Soon, in addition to the elite and a large middle class, Denver had a growing population of immigrant German, Italian, and Chinese laborers, soon followed by African Americans from the Deep South and Hispanic workers. The influx of the new residents strained available housing. In addition, the Silver Crash of 1893 unsettled political, social, and economic balances. Competition among the different ethnic groups was often expressed as bigotry, and social tensions gave rise to the Red Scare. Americans were suspicious of immigrants who were sometimes allied with socialist and labor union causes. After World War I, a revival of the Ku Klux Klan attracted white native-born Americans who were anxious about the many changes in society. Unlike the earlier organization that was active in the rural South, KKK chapters developed in urban areas of the Midwest and West, including Denver, and into Idaho and Oregon. Corruption and crime also developed in Denver.