In the midst of heated legislative proceedings, freshmen members, seeking to catch the eye of the presiding officer so that they might be allowed to address the Senate, have reason to envy a privilege accorded only to the Senate's two floor leaders. At the opening of the 75th Congress, on January 5, 1937, Senate Republican Leader Charles McNary anticipated a difficult session. The 1936 congressional elections had produced a Senate with the lopsided party ratio of 76 Democrats to 16 Republicans. On the first day, McNary counted only one advantage–minor though it may have seemed at the time. He had become the first Republican floor leader to occupy a front-row, center-aisle seat in the Senate Chamber.

Until the early 20th century, the Senate operated without majority and minority leaders. In 1885, political scientist Woodrow Wilson wrote, "No one is the Senator. No one may speak for his party as well as for himself; no one exercises the special trust of acknowledged leadership." In the Senate's earliest decades, chairmen of major committees set the Chamber's agenda. The modern system of Senate party leadership emerged slowly in the years from the 1880s to the 1910s. During that period, both parties organized formal caucuses and selected conference chairmen who began to assume many of the roles of the modern floor leader.

Struggles with increasingly powerful presidents, the crisis of World War I, and the battle over U.S. entry to the League of Nations spurred the further evolution of Senate floor leadership. While party caucuses began to formally designate their floor leaders, they gave little thought to their placement in the Senate Chamber. If the leaders had desired to claim the front-row, center-aisle desks that have become the modern symbol of their special status, the presence of senior members comfortably lodged in those places dashed their hopes.

Finally, in 1927, the senior member who had occupied the prime desk on the Democratic side retired and party leader Joseph Robinson quickly took possession. Republican leaders had to wait another decade, however, before retirement opened up the corresponding seat on their side.

Later in 1937, Vice President John Nance Garner, a former Speaker of the House who valued leadership prerogatives, announced a new policy. Under the Senate rule requiring the presiding officer to "recognize the Senator who shall first address him," Garner established the precedent of giving priority recognition to the majority leader and then to the minority leader before all other senators seeking to speak. These two 1937 developments–priority recognition and front-row seating–contributed greatly to the evolution of modern Senate floor leadership.