Bartenders in the 1800's tended to have something closer to an elemental understanding of types of drinks. But they did not have an especially-wide range of ingredients.
Modern bartending has access to a dizzying array of high-quality ingredients. But it has almost no elemental understanding of the types of drinks.
For example, old-fashioned bartenders, like William Boothby in a very-early published recipe for the Bronx cocktail in 1908, knew that for a cocktail to retain its character as such, only a barpsoon or less of orange juice could be added. Modern drinks writers give recipes with a full ounce, or more, of juice in their Bronx and crusta cocktails - without explaining why they continue such prohibition-era nonsense, or understanding that so much juice overwhelms the cocktail and creates a punch or a sour.
Old-fashioned bartending was often entered through apprenticeship. That ended with prohibition. Modern bartending is still locked in the paradigm of the amateurish side-job bartender, who is often hired for image, personality and speed more than for knowledge.
Old-fashioned bartending is dead. Prohibition was only the last nail in its coffin. Already, in the last decade before prohibition, some books lumped all drinks served 'up' together as 'cocktails.'
I have yet to find a single establishment that combines the great ingredient selection we have today with the old-fashioned understanding of different types of drinks and how best to make and serve them.
I have found several establishments that sell the image of old-fashioned bartending, but they all fall short before the knowing eye. The tradition died. There was no living link through the generations. And so now, those wishing to sell what they do as old-fashioned bartending are reduced to reading old books. Unfortunately, all of us read the old books through modern bartending assumptions. We should be aware that those assumptions are from the debased, amateurish bartending that has been American bartending since 1934.
That the re-discovery of fresh juices is often touted as proof of good bartending is very sad. This is how remedial our education must be. Should we, as American bartenders, really be proud that, until recently, imitation ingredients were the norm? Should a man be proud that he stopped beating his wife last week? Wouldn't it be better to switch back to all fresh juices and not make a big deal of it?
But, now that it has re-discovered fresh juices, modern bartending tends to make everything into some sort of punch. It's as if we are doomed to go back and repeat all drink evolution since the 1600's, let alone the 1800's!
We should be able to do better than bartenders in the 1800's, simply because of the quality and diversity of what we can work with. But before we can get there, we need to re-learn almost everything.