At the start of each Congress, the Senate Chamber desks are reapportioned between the two sides of the chamber based on the number of senators from the two political parties. Historically the desks were assigned on a first-come, first-served basis. When a seat became available, the first senator to speak for it won the right to it. Today, at the beginning of each Congress, senators are given the option to change their seats, based on seniority. Three desks that are not assigned in this manner are the Daniel Webster Desk, Jefferson Davis Desk, and the Henry Clay Desk. The assignment of these desks is governed by Senate resolutions.