Could you imagine back in the early days being required to unload and place your handgun in a locked strongbox every time you left your home via horse or buggy?
I kinda doubt the RKBA was restricted to your home, but that seems to be the defacto case in much of the US.
What do you mean by the old days? Lincoln was in favor of banning all civilian firearm ownership. Somebody shot his hat off once as he was riding through Washington. That probably had something to do with it.