census
Congressional districts are reapportioned every ten years. This coincides with the mandated census. It is done to adjust for population changes.
State legislatures redraw the congressional districts every ten years.
The number of congressional districts per state is determined every 10 years, after the census.
Congressional districts are redrawn every 10 years following the national census. This process is called redistricting, and the U.S. Constitution requires a census every 10 years for the purpose of redistricting Congressional districts.
Every 10 Years
The U.S. Census is used to tell which states grew to get representation and which states lost population and therefor lose some representatives
They are elected every two years from their congressional districts. Every state has at least one district and the others are awarded based on population given by the official census taken every ten years.
Each state has two senators, but the number of congressmen are determined by population based on census figures. For instance, Mississippi had five congressional districts from 1960 to 2000. But one district was abolished when the 2000 census showed that the state had lost population.
Congressional districts must have nearly the same number of residents. This can't be exact because districts are reapportioned after the census every ten years.
Each state has two senators to the federal senate in Washington, D.C. Every state has a constitution that will set forth how its senatorial and congressional districts are set up as far as state government goes.
The number of Representatives in the US House is set by law at 435 members. Based on new census numbers every ten years, the house districts are re-allocated between the states to create districts of even populations. Since some states have big increases in population while others may have declining populations, there is generally a shift in the number of congressional seats among the states, with some states gaining seats and others losing seats. Each district represents approximately 700,000 people. California currently has 53 congressional districts, while Vermont and Wyoming have only one each.
The total number of Congressional districts is set by law, currently at 435, but it can be changed by an act of Congress. For example, there was a recent proposal to give Washington, D.C., a full voting member of Congress, and also add one more seat elsewhere, raising the total to 437.