Origin of 'gin up'

I have been reading the Ken Follet 'Century' saga, and came across a usage I had not seen before. Supposedly in the words of an American...

He had different governmental departments working together to target individual heads of crime families. The Federal Bureau of Narcotics had been "gingered up". The Bureau of Alcohol, Tobacco, and Firearms had been enlisted.

As an American, I have never heard this usage before. Instead, what I have always heard used in a case such as this...

gin up

in slang phrase gin up "enliven, make more exciting," 1887 (ginning is from 1825), perhaps a special use of the verb associated with gin (n.2) "engine," but perhaps rather or also from ginger up in the same sense (1849), which is from ginger in sense of "spice, pizzazz;" specifically in reference to the treatment described in the 1796 edition of Grose's slang dictionary under the entry for feague: ... to put ginger up a horse's fundament, and formerly, as it is said, a live eel, to make him lively and carry his tail well; it is said, a forfeit is incurred by any horse-dealer's servant, who shall shew a horse without first feaguing him. Feague is used, figuratively, for encouraging or spiriting one up. [emphasis mine]

Etymonline

Although interesting, this entry is not really definitive, and seems to be more concerned with feague...

Does the American usage of "gin up" derive from the old British horse racing practice of sticking ginger root up a horse's butt, or does it come from 'engine' e.g. Eli Whitney and his amazing machine?

To me, it seems like Grose's Dictionary of Slang was a little like the Urban Dictionary of its day, and may have been stretching the point.

Solution 1:

Most sources tend to cite both supposed origins, engine or ginger up, but the Word Detective tends to give more credit to the former one since engine originally meant intelligence or inventiveness, as explained below:

The first traces “gin up” to the noun “gin,” a short form of “engine,” which originally simply meant “intelligence or inventiveness” (from the Latin “ingenium,” which also gave us “ingenuity”). “Engine” in the derivative sense of “machine,” a product of such inventiveness, dates back to the 14th century. The shortened form “gin” has meant “skill or ingenuity” since the 13th century when “to gin” was also used to mean “to start up or begin.” It is possible that “gin up” in the sense of “create excitement” comes from this “start” sense. It is also possible that “gin up” was inspired by the “cotton gin” (short for “cotton engine”), a machine used to remove the seeds from cotton in the American South in the 19th century. As of 1887, “to gin” meant “to work hard” or “make things hum” like a cotton gin in operation.

Solution 2:

In addition to @user66974's quotation comment-answer I suppose both hypothesis, either engine or ginger could be related, eventually.

The reason being, there is a row of words pertaining to beginnings summed-up with the reconstructed Proto-Germanic word *ginnaną, further etymology uncertain. It has been conjectured to root in Proto-Indo-European *ken-, but the semantics and form of this are--maybe not so obvious--rather reminiscent of PIE *'genH-, whence e. g. kin, genesis and indeed ingenius. Wiktionary names problems with genius however, noting the different semantics for Latin genius,