Say no more, really. But if you must, this blog explains:

An all-nighter of renown in the 20th century was Coffee Dan’s, originally in San Francisco, which operated as an eating and entertainment venue, then a speakeasy in the 1920s and early 1930s. Its attitude in the mid-1920s is nicely expressed in the claim, “There will be dancing to the tinkle of a piano; there will be songs and it will never, never close, not even for fire, not even if the supply of ham and eggs is exhausted.”

Because there will still be coffee.

More here, including a picture of Dan - who died in 1917.