Following the Sonderbund War in 1847, the Tagsatzung became responsible for drawing up the Swiss Federal Constitution.

After long debates, a compromise was found by adopting the American model of bicameralism; the parliament will be composed of two chambers with equal power, and the agreement of both will be required to take a decision.

[3] This number was not fixed and evolved in proportion to the growth of the Swiss population until 1962 when the definitive number of seats was established at 200; the term of office, meanwhile, was increased from the original three years to four years in 1931.

The mode of election, originally according to the majority system, transitioned to proportional representation in 1918.

[4] The Council of States, meanwhile, was not modified until 1979, by adding two new seats for the Canton of Jura which had just been created.

[3] The Federal Assembly is made up of two chambers: Seats in the National Council are allocated to the cantons proportionally, based on population.

On occasions the two houses sit jointly as the "United Federal Assembly" (German: Vereinigte Bundesversammlung, French: Assemblée fédérale, Chambres réunies, Italian: Assemblea federale plenaria, Romansh: Assamblea federala plenara).

Members of the National Council are required to be in a formal group in order to be able to sit on a committee.