Which is the oldest bar in Chicago?

I think the oldest bar in Chicago has to be the Schaller's Pump . This bar is in Chicago’s Bridgeport area and first started serving customers in 1881. It even continued operating during the period of prohibition. At that time you had to be screened through a peephole in the wall.

It was during prohibition that the bar got the “Pump” added to its name when the next door brewery pumped beer directly into the bar. It's a place long favored by the Democratic party of Chicago—apart from its readiness to serve, it’s only a stone’s throw from the 11th Ward headquarters—very convenient! In fact, the Schallers Pump was used as the second office for a number of Chicago’s mayors.