Green’s Dictionary of Slang

to do something outstanding; thus that beats the Dutch, describing something that is otherwise barely credible; to beat the Dutch, to the utmost, very much.

1775		revolutionary song in New England Historical Register Apr. (1857) 191: Our cargoes of meat, drink, and cloaths beat the Dutch.
1837		Public Ledger (Phila.) 6 Feb. n.p.: ‘That beats the Dutch,’ saith the proverb; meaning that, as the Dutch beat Old Nick, it is something of an exploit to beat them.
1840		Knickerbocker (N.Y.) xv Feb. 127: Of all the goings on that I ever did hear of, this beats the Dutch.
1854		Knickerbocker (N.Y.) xliii May 524: Well, it does beat the Dutch, and the Dutch, you know, beat the d—l.
1862		in R.G. Carter Four Brothers in Blue (1978) 15–16 Nov. 163: We found him a queer genius in his ideas, and in politics he beats the Dutch.
1872		Schele De Vere Americanisms 83: One would almost imagine that the Dutch of old must have been greater people than even the Knickerbocker Annals give them credit for – how else could the phrase: That beats the Dutch, have obtained such general currency?
1879		Luton Times 5 Dec. 7/6: ‘That beats the Dutch,’ as the Teutonic hotel-keeper said when one of his guests left [...] forgetting to pay his bill.
1884		M.V. Fuller Mrs Rasher’s Curtain Lectures 56: Well, if that don’t beat the Dutch!
1891		Lancs. Eve. Post 6 Mar. 2/4: ‘He is as obedient as any son could possibly be.’ ‘Well [...] that beats the Dutch’.
1902		Knickerbocker (N.Y.) Apr. 392: Guess she must a-had Secesh beaux, / And gone to Jayhawker parties from her youth up. This bangs the Dutch of St. Louis, / And they kin swear some.
1909		W.M. Raine Brand Blotters (1912) 28: He had ridden twenty-seven miles to see Melissy Lee and he had not quite expected this sort of a greeting. ‘If that don’t beat the Dutch.’.
1918		E. O’Neill Rope (1923) 26: Hahaha! If that don’t beat the Dutch!
1926		Wood & Goddard Dict. Amer. Sl. 5: beats the devil, the Dutch. Beats everything.
1936		(con. 1920s) Dos Passos Big Money in USA (1966) 967: I thought we were in pretty good shape out at Long Island City . . . but this beats the Dutch.
1939		P.G. Brewster ‘Folk “Sayings” From Indiana’ in AS XIV:4 267: If it is startling news, it ‘beats the Jews’ or ‘beats the Dutch’.
1940		H.W. Thompson Body, Boots & Britches 450: A group from New England who, slightly in the Majority, agreed on a classical name ‘to beat the Dutch’.