What does "and how" really mean? [closed]

I'm reading it as "And to what an extent!"

Dictionary of Idioms - Page 85 Martin H Manser - 2006

And how! Very much so: used to express strong agreement with what has just been said, but sometimes also used to express the opposite of this: > 'Goldie's beautiful, isn't she?' 'And how!'

According to J. E. Lighter, The Random House Historical Dictionary of American Slang (1994), the phrase has an interesting past:

and how interj[ection] {trans[lation] of G[erman] und wie!; not fr[om] Yid[dish], as sometimes thought} emphatically so; yes, indeed. {This phr[ase] suddenly gained wide currency in the 1920's. No citations are known between 1865 and 1926.}

[First three citations:] 1865 in A[merican] S[peech] (Dec. 1933) 80: And how? as the Germans say (Americanicé—"you'd better believe it!") 1926 Variety (Apr. 7) 23: "Kongo" is a melodrama—and how! 1928 McEvoy Show Girl 33: Are you mixed up in this? ...And how.

Robert Hendrickson, The Facts on File Encyclopedia of Word and Phrase Origins, revised edition (1997) has this entry for the phrase:

and how! Indicating "intensive emphasis of what someone else has just said," and how! is a long-popular catchphrase first recorded in 1924. The Americanism possibly derived from the German und wie! or the Italian e come!, meaning the same thing, and once very common among Americans of German and Italian extraction, respectively.

Unfortunately, Hendrickson doesn't identify the 1924 occurrence. A Google Books search for "and how" across the years 1921–1926 yields no matches for the phrase in the relevant sense, corroborating the main thrust of Lighter's observation above.

If the phrase really is a direct translation from a German or Italian phrase, the quest for an explanation may stop there. If it is an Americanism, perhaps it adopts the same semi-sensical approach to meaning as (for example) the later expression "what it is!"