1. Gerrymandering

2. Reapportionment
The reallocation of the number of representatives each state has in the House of Representatives.
Census data is used every 10 years to reallocate the 435 seats in the House.
Visit:
and click on Congressional Apportionment, and look at figure 1.

3. Redistricting
The drawing of House / Congressional (not Senate) district line.
This is done every 10 years after reapportionment.
It is usually done by the state legislature.

4. Gerrymandering
Drawing the boundaries of legislative districts in bizarre or unusual shapes to favor one party.
Baker v Carr (1964): “one person, one vote.”
Video explanation:

5. San Marino’s District 27

6. A final article and video on gerrymandering