Why meet in closed session? The Constitution does not require Congress to meet in public. The House of Representatives, elected directly by voters, immediately opened its doors to the public and press. Senators, originally chosen by state legislators, decided to meet in private, believing they could work more efficiently without public scrutiny and interference.
The earliest Senate Chambers, in New York City and Philadelphia, did not have visitors’ galleries. The Senate decided to build a viewing area in 1794 after many state legislatures and newspapers demanded more openness. Beginning in 1795, the Senate debated legislative business (lawmaking) in open session but continued to discuss executive business (treaties and nominations) in closed sessions until 1929. Today, both houses of Congress conduct all debates in public sessions, except when discussing information that could risk national security.