Article 1 Section II talks about how a census (every 10 years) was to determine how many seats a state was entitled to. At first, no thought was given to gerrymandering which is the act of setting up distracts that would favor the governing party in power. This problem was partly addressed by limiting the number of congressmen to 435 and letting the census determine how the population would divy up how many congressmen each state was allowed. I cannot find how that works or whether or not the constitution was amended to bring the 435 about. It can be found in the legislation of 1929.