Q:

When did it become acceptable to campaign for yourself for US President?

I am fascinated by the stark differences between election mechanics/strategies/policies of the early United States when compared to today.
In the early days of the US, it was seen as "ungentlemanly" to campaign before a presidential election.  I know that Washington, Adams and Jefferson all stayed out of the fray; though perhaps surreptitiously directing subordinates to do the campaigning work.
Now, of course, campaigning for president is a more-than-full-time job.
How long did this difference last?  When did it become acceptable to even acknowledge that you want the post?

A:

My understanding, as confirmed by your intuition and this article in the New Yorker exploration into presidential biographies starting with John Eaton's 1817 work "Life of Jackson" was that it wasn't until 1824 that attitudes on running a presidential campaign substantially changed.  From said article,

The election of 1824 brought the first campaign buttons, the first public-opinion polls (undertaken by and published in pro-Jackson newspapers), and the first campaign biographies. Eaton’s “Life of Jackson” was the one that established the genre’s enduring conventions.

From reading, Jon Meacham’s “American Lion: Andrew Jackson in the White House” I can tell you that Jackson played an active role in the attacks of pro-Jackson papers on his political opponents.  I also seem to recall the book mentioning he made campaign stops, but I'm not 100% on this so take this claim with a grain of salt (or better reference the book!).  What I can say is that it would make sense that Jackson's campaign changed the way presidential races were run, as he had would go on to be instrumental in radically changing the US presidency especially in terms of its scope, perceive importance, and its duties.  
Read more "Bound for Glory. Writing campaign lives." By Jill Lepore, New Yorker, October 13, 2008.

A:

If your question is specifically about the candidate hitting the campaign trail and personally campaigning then the answer is the election of 1880.
According to the Miller Center at the University of Virginia during the election of 1828 "neither candidate personally campaigned in 1828, but their political followers organized rallies, parades, and demonstrations." So it seems unlikely that anyone personally campaigned prior to this election. Additionally, since Jackson didn't campaign in 1828 he probably did not do so in 1832 either.
I looks like Winfield Scott was the first presidential candidate who campaigned around the country during the election of 1856. However, his opponent Franklin Pierce did no campaigning of his own so it would be a stretch to say that the practice was acceptable.
It was not until the election of 1880 that both candidates (Winfield Scott Hancock and Chester A. Arthur) campaigned around the country. 

