The first Rotary Club was organized by Paul Harris on February 23, 1905 in Chicago. As the number of clubs grew, they were assigned to geographical districts to make management and operations easier. Club numbers often reflect the seniority of the clubs. For example, the Chicago club is #1; more recent clubs number nearly ninety thousand*.
District 751 was then renamed District 7510.
* - Because clubs sometimes re-charter due to such things as adding new territory, club numbers do not always reflect the actual seniority of the original club. For example, the Rotary Club of Plainfield was originally chartered in 1921 with #1026. The club changed its name to Plainfield-North Plainfield in the 1980's to reflect its broader base and was assigned #5656 as its newly-chartered number.