Oklahoma County came about by the Organic Act of Congress on May, 1890. Originally Oklahoma County was designated as “County Number 2”, but was changed by a vote of the people renaming it to Oklahoma County. The original county offices were located in an office building located at California and Robinson Streets, then relocated into the first Oklahoma Courthouse sometime after construction began in November 1904 and prior to state hood in 1907. The first actual courthouse was located at 520 West Main Street. This magnificent structure served as the county courthouse until 1937.
The first county courthouse, in 1890, was a building rented from Henry Overholser, located at Robinson and Grand (now Sheridan).
Skipping ahead seventeen years, the county built a courthouse in 1907 at Main and Dewey where the following Centennial (1989) article begins: Existing now only in newspaper files, books, artwork and the memories of old-timers, the original Oklahoma County courthouse once dominated the Oklahoma City skyline just a block from the present county courthouse.
Construction of the building which began November 4, 1904, cost Oklahoma County taxpayers $1,000,000. Located between Main and Grand (Sheridan), the ornate building entrance faced Dewey, it's west boundary. That feature was the result of a compromise between Main Street merchants, who insisted the entry face Main, and Henry Overholser, a county commissioner who felt the courthouse entry should enhance the social center of Oklahoma by facing his opera house on Grand Avenue.
The new courthouse still in use today, was officially dedicated for public service of the local city-county government building by the famous Democrat , President Franklin Delano Roosevelt in the spring of 1938. His dedication left Oklahomans feeling proudly confident.
This information is from Judge Halls book “A History of Judges of Oklahoma and Canadian Counties” Vol I 2005