Illinois is a very rare name used for both girls and boys that was most common in the 1920s and has all but disappeared.
Illinois is predominantly a girl name. It last appears in U.S. records in 1923. Illinois was first reported in SSA data in 1918 and peaked in 1920 (6 births).
Girls named Illinois per year · hover for count and girls rank · Source: U.S. Social Security Administration, national data 1918–1923 · U.S.+territories from SSA territory files (1998–1923) · SSA publishes a name only in years it was given to at least 5 babies, so a name may have been in use before — or between — the years shown here
Boys named Illinois
Boys named Illinois per year · hover for count and boys rank · Source: U.S. Social Security Administration, national data 1918–1923 · U.S.+territories from SSA territory files (1998–1923) · SSA publishes a name only in years it was given to at least 5 babies, so a name may have been in use before — or between — the years shown here