Let’s talk CB radios

My first CB was a 6 channel Johnson .

Late 70's I had a Courier 23 channel with another 46 channels added on using a 500 watt kicker.

I had 6' heavy duty antennas that I had to swap out because of low bridges coming into Milwaukee..

I used to talk to guys fishing in the Gulf of Mexico and a few guys in Cuba on occasion.

I still have a 23 channel Cobra sideband radio I bought new in 1974.
How did you reach so far? Amplifier?
I thought you could only reach a few miles.