Betsy Ross

History

This combination of brandy, port and curaçao is also known as the "Imperial": indeed, it first appears under that name in William "Cocktail Bill" Boothby's posthumously published 1934 World's Drinks And How To Mix Them.

IMPERIAL
Cognac . . . . . . . . . . 1/3 jigger
Port Wine . . . . . . . . 1/3 jigger
Curacoa . . . . . . . . . . 1/3 jigger
Shake well with ice, strain into chilled cocktail glass and serve.

William Boothby, 1934

It then appears (in line with the proportions I favour) under the name Betty Ross in the 1932-1933 season menu of Cuba's famous Sloppy Joe bar.

BETTY ROSS
One half glass of Fundador Cognac.
One half glass of Oporto Wine.
Drops of Curacao.
Drops of Angostura Bitters.
Shake with cracked ice and serve in a Manhattan glass.

Sloppy Joe Bar menu, 1932

In 1940, this cocktail appeared again, titled Betsy Ross (the name it's known by today) in Crosby Gaige's 1940 Cocktail Guide and Ladies' Companion.

Betsy Ross Cocktail
1 jigger Brandy
1 jigger Port Wine
2 dashes Angostura Bitters
Dash of Curaçao
Stir well in cracked ice and strain into large cocktail glass. Try this one with the yolk of 1 egg and 1 teaspoon sugar. Sprinkle a grating of nutmeg on the top of each glass. In any event you don't have to buy lunch.

Crosby Gaige, Crosby Gaige's Cocktail Guide and Ladies' Companion, 1940

Who was Betsy Ross?
Legend has it that Betsy Ross sewed the first U.S. flag. There's no evidence to support this, but she was the niece of George Ross, the Founding Father of the United States, who signed the United States Declaration of Independence as a representative of Pennsylvania. She is also known to have prayed in the pew next to George Washington and had sewn buttons for him.

It's probable that the members of the Flag Committee formed by the Continental Congress asked Betsy to sew the flag and in an affidavit made public in 1870, Betsy Ross's daughter, Rachel Fletcher, testified: "[The committee] showed her [Betsy Ross] a drawing roughly executed, of the flag as it was proposed to be made by the committee, and that she saw in it some defects in its proportions and the arrangement and shape of the stars. That she said it was square and a flag should be one third longer than its width, that the stars were scattered promiscuously over the field, and she said they should be either in lines or in some adopted form as a circle, or a star, and that the stars were six-pointed in the drawing, and she said they should be five pointed."