7up contained lithium citrate, a mood-stabilizing drug, until 1948
en.wikipedia.org
en.wikipedia.org
A lot of the early sodas were developed and sold by pharmacies as tonics. Healing, medicinal, feel good, and so on.
A far cry from today's pure sugar rush and crash.
At least here in the UK you will struggle to find the "original" version of many sodas with refined sugar in them. Almost all have been replaced with the "artificial" sweetener version. Most places often don't even have original coke, only stocking coke zero or diet.