jack = 'quit; give up'

[Jonathan Lighter]

Not in HDAS and quite unfamiliar to me, but the context suggests that
it wasfamiliar in Main in 1919:

1919 _Daily Kennebec Journal_ (Jan. 31) 6 [NewspArch.]: Since he
jacked his job in Ginn & Co.'s publishing house in Boston when the war
broke out...life has been one grand adventure for young Wescott. He
longed for action and [etc., etc.].

JL

--
"If the truth is half as bad as I think it is, you can't handle the truth."

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