National League Office.

In the wake of the Black Sox scandal and their dissatisfaction with Ban Johnson, the National League wanted to reorganize Major League baseball. A revised agreement with the National Association was drafted as well as a revised National Agreement and rules. The Lasker Plan recommended that baseball's governing authority be reformed, which led to the creation of the Commissioner's office.

From the description of National League Files: Reorganization of Baseball : papers 1918-1921. (National Baseball Hall of Fame). WorldCat record id: 754656698