Green’s Dictionary of Slang

1. drunk, thus how-came-you-soish.

1770		Gent.’s Mag. 559: To express the condition of an Honest Fellow, and no Flincher, under the Effects of good Fellowship, it is said that he is [...] A little how came you so?
1804		C.L. Lewes Comic Sketches 26: While others would say he had, ‘Bung’d his eye — Was knocked up — How came ye so — Had got his little hat on — Top-Heavy — Pot- Valiant — That he had been in the sun — That he was in for it’.
1824		T.E. Hook ‘Merton’ Sayings and Doings 1st Ser. III 89: Ould Mrs. Etherington was a right bad one; she used to be – ‘Lord, how come you so!’ every night, as regular as she went to bed.
1825		Pierce Egan’s Life in London 25 Dec. 382/1: [T]he complainant, who was in a very how-came-ye-soish sort of a condition, [...] assaulted them.
1830		Egan Finish to the Adventures of Tom and Jerry (1889) 187: The Oxonian was getting ‘how come you so?’ Jerry was terribly cut.
1837		N.Y. Times 9 Jan. 3/1: [A watchman,] hearing a bit of a shindy at a house occupied by a couple of ‘darkies,’ [entered, and] found both husband and wife pretty well ‘how come you so’. [Ibid.] 4 Mar. 2/6: Ald. Wheeler met a man much ‘hacomo you so’? [sic] that he was in danger of falling under the wheels of a Bowery omnibus.
1842		Manchester Courier 5 Mar. 3/2: Drunk— [...] How came you so?
1842		Whip & Satirist of NY & Brooklyn (NY) 5 Feb. n.p.: Phebe was in a state of how come you so, which surprised us much.
1845		Hants Advertiser 10 May 8/2: [She] was charged by P.C. Fish with being found in a state [...] of ‘How came you so’.
a.1856		Burlington Sentinel in Hall (1856) 461: We give a list of a few of the various words and phrases which have been in use, at one time or another, to signify some stage of inebriation: [...] how come ye so [...] how fare ye.
1858		Sussex Advertiser 24 Aug. 2/2: Both parties had by some means gor into a state of ‘How came you so’.
1864, 1867, 1870		Hotten Sl. Dict.
1870		Berwicks. News 1 Feb. 6/5: Policeman— ‘Ullo! How come you so, guvbnor!’ Individual— (dreadfully typsy): ‘’xhaustion - sheer exhaustion!’.
1886		Leeds Times 17 Apr. 6/5: You friends, if they have kept up with you, will be in a very ‘how-come-you-so’ condiction.
1895		Manchester Courier 8 June 10/3: The latter was very much ‘how cam you so’.
1898		F.P. Dunne Mr Dooley in Peace and War 136: He was in here las’ night, how-come-ye-so, with his hat cocked over his eye.
1911		J.C. Lincoln Cap’n Warren 223: One evenin’ Labe was coming home pretty how-come-you-so and he fell into Jandab Wilson’s well [DARE].
1968		in DARE.

2. (US) whisky.

1850		Life in Boston & N.Y. (Boston, MA) 7 Sept. n.p.: Some of them indulge in the sweets of Bacchus [...] and even keep a jug of the ‘how came you so’ by them!
1943		(con. 1861-5) B.I. Wiley Life of Johnny Reb 70: Very rarely an officer or private sneaks a swig of ‘How Come You So’ to bolster his spirit.

3. (US) pregnant.

1923

DN V 240: How-came-you-so [...] Pregnant.