What is the origin of "moral support"?

Why is the phrase "moral support" used, when it seems like it would more accurately be "morale support"?

Is this just a misspelling that has become canon, or something else?

According to the Online Etymology Dictionary, moral originally meant "pertaining to character as opposed to physical action." It did not originally relate to social values or manners. So moral support means support that is intangible rather than financial, military, or other physical support.

I found this through Dictionary.com: http://dictionary.reference.com/browse/moral.

Etymology Online says that the original meaning of the word "moral" was

"pertaining to character or temperament" (good or bad)

And that this meaning is retained in the phrase "moral support":

with sense of "pertaining to character as opposed to physical action."

Moral support means "support or help, the effect of which is psychological rather than physical."
Morale means "the confidence, enthusiasm, and discipline of a person or group at a particular time."

Their morale was high.

Morale support is not a phrase I have ever heard, and it would not have the same meaning of moral support.