The purpose of the Chicago zoning ordinance (CZO) was to promote and protect the general public welfare, promote stability within the residential, commercial, business, and manufacturing areas, and to promote their orderly and beneficial development. The CZO permitted churches as of right in all residential zones but required special use permits in commercial and business zones. The process of getting approval for a special use permit approached $5,000. A church in a manufacturing zone or some commercial zones would require rezoning. Chicago (defendant) later amended the CZO to require all clubs, lodges, meetings halls, and community centers to obtain special use permits in all the areas in which a church was required to obtain one. The Civil Liberties for Urban Believers, an association of Chicago-area religious or non-profit corporations, along with five individual member churches (plaintiffs), challenged the CZO on several grounds: violation of the federal Religious Land Use and Institutionalized Persons Act (RLUIPA), the free exercise of religion, and the Equal Protection Clause of the Fourteenth Amendment. The trial court granted summary judgment for the city on all counts, saying the CZO imposed no substantial burden on religious exercise, was rationally related to a legitimate government purpose, and was a neutral and generally applicable law that did not impermissibly burden religious exercise. Plaintiffs appealed.