Why do I have to dial '1' for long distance on a land phone, not on a cell phone?

The phone company should follow the lead of the cell phone companys. I forget many times to dial the '1' on my land phone. Frustrating.

No. None of those answers are close to be correct. The answer lies on how the phone number is entered.

On a landline, it's processing the phone number on the fly. Meaning, it is trying to route your call as you enter each number. So, in order for the system to realize that you are making a call outside of your area and thus having your local switch interface with another switch elsewhere, you have to dial "1" to tell the switch that this is going to be a long distance call, so not only should it anticipate to communicate with another switch outside the local area, but also expect 10 more digits to come.

If you don't dial the 1 and just start dialing, the switch will only listen for the first 7 digits it hears and try to connect the call regardless of what other digits you keep entering. That is provided that you don't live in a multi-area code area and you happened to dial the correct area code to tell the switch to listen to anticipate 10 digits total.

That's also why there is a dialtone. It's called a dialtone simply because when you hear that noise, the phone company is basically telling you that it is now ready to start listening to the tones from your phone to figure out who you are calling. That's why when you enter the first digit, the dialtone goes away. This is cause it is telling you that it has registered that first entry and is already processing what to do with your call.