The Civil War pensions disappeared over time and other support mechanisms were ruptured by the Great Depression. The invention of Social Security was a response to this economic crisis, but even if the Great Depression had never occurred, it is doubtful that the traditional system could have endured the very rapid growth in life expectancy. As the elderly population grew, they became harder and harder to support through traditional mechanisms, even at low living standards. Incidently, Japan does have a Social Security system that in some ways is more generous than ours. Unfortunately this is not politically viable.
Personal accounts are at least a movement in the direction toward increased liberty.
A system of mandatory individually owned, privately invested accounts would not do anything about the first element, but it would eliminate the second and third, thus increasing individual liberty to a significant degree. Prior to the creation of Social Security in the thirties approximately half of the elderly lived in poverty. Currently just over 10.0 percent of the elderly live in poverty, just about the same as the rest of the adult population. It has provided hundreds of millions of retired workers with a decent retirement over the last sixty years, with a minimum of fraud and abuse. If the politicians leave just leave Social Security alone, it can continue to guarantee workers a secure retirement for another sixty years.