Not a stupid question. Our government is confusing. It's basically still being carried out verbatim, and the entire thing was built and architected in an era when the fastest anyone could travel is by speed of wind.
In the US, government is generally federalist, meaning, each state is its own independent entity (legally speaking) with the autonomy to describe, create, and manage laws specific to their culture in their state. This boils down even further with municipal zones, which are typically related to city or township governance (covering shit like local police, trash, fire, streets).
Each state has the power to define both its voting districts, as well as the way they vote. For example, states in the West traditionally had fewer people over sparser distances, so traditional paper balloting was foregone in lieu of 'caucusing,' which is literally about measuring the amount of bodies or the scale of voices.
In the early 1800s (roughly 40 years after the founding of the country we know now), a man named Eldridge Gerry figured out that it was technically legal under federal law to flip the way districting happens on a per-state basis — instead of people choosing their district, the district chooses its voters.
So, over time, Gerrymandering proved to be one of the only successful ways to gain an edge in a population where conservatism was shrinking and leftism and socialism were building in popularity. It has continued simply because it is a foundation of power in our bicameral (two parties) system.
Just FYI, it is so named "Gerrymandering" after Eldridge Gerry, as well as the fact that his resulting districts looked on a map like a slithering salamander.
You still need states to ratify what was passed during the convention anyway, and even then, it has to be ratified in 3/4s of states, and 9 of the top 10 earners in the US economy are solid blue states with strong blue state governments. 🤷