I have about 1 acre of lawn that I mow. The lawn is extremely bumpy. I have read that you should not roll the lawn, but instead aerate.

Any suggestions?
Thanks

First of all neither rolling nor aeration are designed to level the ground the grass is growing in.

I had this issue in the yard of our 2nd home. All the sources I checked with left me with this: There's no simple solution.

Topsoil and seeding can work in low areas, but if it's just "generally bumpy" then you're either stuck with living with it or removing all the grass, leveling the ground with soil and replanting or sodding.