There were Jews living in Sioux City as early as the 1860s, but a synagogue was built in the city until 1884. Adas Jeshurun was an Orthodox congregation. The Jewish community in Sioux City grew from 200 in 1890 to nearly 2,500 by World War I. Sioux City was home to the second largest Jewish community in the state of Iowa at the time. Mount Sinai Temple was established in 1901. The synagogue, which opened the same year, was expanded in 1922. The building was designed in the Prairie School style. Between World Wars I and II the Jewish Community Center in Sioux City hosted 60 to 70 clubs, classes and organizations that ranged from socialist workers to Zionists. A one-mile section of West Seventh Street was home to 22 Jewish owned businesses in 1944.
After World War II the Jewish community in Sioux City began to decline. By the mid 1980s the population was down to 700 people, and by 2001 it was down to 300. The Jewish congregations in Sioux City combined their religious schools in 1990. Four years later the congregations themselves merged at Beth Shalom, the Conservative synagogue.