$ info Groff | awk '$2 == "History"{f = 4};f && f--' RS= ORS='\n\n'
    1.2 History
    ===========
    
    'troff' can trace its origins back to a formatting program called
    'RUNOFF', written by Jerry Saltzer, which ran on the CTSS (_Compatible
    Time Sharing System_, a project of MIT, the Massachusetts Institute of
    Technology) in the mid-sixties.(1)  (*note History-Footnote-1::) The
    name came from the use of the phrase "run off a document", meaning to
    print it out.  Bob Morris ported it to the 635 architecture and called
    the program 'roff' (an abbreviation of 'runoff').  It was rewritten as
    'rf' for the PDP-7 (before having UNIX), and at the same time (1969),
    Doug McIllroy rewrote an extended and simplified version of 'roff' in
    the BCPL programming language.
    
       In 1971, the UNIX developers wanted to get a PDP-11, and to justify
    the cost, proposed the development of a document formatting system for
    the AT&T patents division.  This first formatting program was a
    reimplementation of McIllroy's 'roff', written by J. F. Ossanna.

[Edit]: Indeed, I ran your command verbatim and obtained one more paragraph: When they needed are more flexible language [...].

You sneaky devil!

He he. Never copy/paste shell code found on the internet :-)