Who named the Democratic Party?

It seems to me that the Democratic Party was not named per se. Instead, it gradually settled upon its present name more or less between 1824 and 1844. As is well known, the original Republican Party largely collapsed into personality-centric factions after 1824. The resulting fledgling parties, however, continued to profess membership in the old Republican Party.

Accordingly, the Jacksonian faction (and future Democratic Party) formally considered itself the Republican Party. This official line remained the dominant narrative into the 1830s. For example, their first national convention in Baltimore, 1832, was titled, "A Convention of Republican Delegates From the Several States in the Union". There was no mention of a Democratic Party yet.

At the same time, names were more fluid on a regional level, where some incorporated the originally-derisive Democratic as a prefix. This wasn't a new development: local organisations of the party seemed to have been doing that since as early as 1798. The resulting name, the Democratic-Republican Party, was rare during the early 1800s but gained ground after 1824. Notably, it became the chief self-identification of Jacksonian supporters in Pennsylvania during 1824.

The delegates appointed by the democratic republicans of this state, met at Harrisburg on the 4th inst. All the counties were represented but four, and the amount of delegates present was one hundred and twenty-five ... a resolution then prevailed for the support of Andrew Jackson.

_{- Niles' Register, March 13 1824}

A similar development saw the National Republican name became particularly associated with the Anti-Jacksonian faction in 1830. There was clearly a need for easier identification of the splintered Republican faction/parties. The Democratic vs National Republican divide offered exactly that. When the campaign of 1832 arrived, therefore, the Democratic-Republican label surged in popularity.

It is a very small leap to go from Democratic Republican Party to simply Democratic Party, and the latter term also grew in popularity. This mirrors earlier developments at Pennsylvania, where the 1828 state convention was simply named the "Democratic Convention", for example. It is also around this time references to "the great Democratic Party of the Union" began to crop up.

Jackson, like those made by president Jefferson, were the legitimate results of the previous system of appointments, and were necessary not only to the safety and success of a democratic administration, but due as an act of justice to the great democratic party of the union.

_{- Niles' Register, June 20 1835}

He found men there to persuade him, that a caucus of eleven members of Congress was a more suitable body to bring out a candidate for the Presidency, than a National Convention of Delegates - the representatives of the great Democratic party of the Union.

_{- Extra Globe (September, 1835)}

Note that party officially continued to style itself Republicans through the decade. For example, the 1835 national convention in Baltimore informed its Vice Presidential choice that:

A convention of republican delegates from various parts of the union, for the purpose of selecting suitable candidates for the office of president and vice president, assembled in Baltimore on the 20th instant, and agreed to present to their country, your name for the of vice president of the United States.

_{- Niles' Register, July 11 1835}

Official attitudes caught up with popular usage by the time of the 1840 convention. That event appears to be the first to be titled the Democratic National Convention. The party did continue to make sporadic references to being Republican, apparently treating it as a synonym. However, by this stage Democratic Party had clearly became the favoured name, a situation reinforced in the 1844 convention.

Other Views

According to the Library of Congress, the name of Democratic Party was officially adopted during their National Convention in Baltimore, May 1832.

The Democratic convention of 1832, held on May 21 - 22 in Baltimore, is notable as the convention where the Democratic Party formally adopted its present name. The party had previously been known as "Republican Delegates from the Several States."

_{- Library of Congress. "Democratic National Political Conventions 1832-2008." Library of Congress.}

In contrast, several other writers listing the dates as 1840.

The Democratic convention was held in Baltimore in May 1840. It was at this convention that the party's name was offficially changed from Democratic-Republican Party to Democratic Party.

_{- Wagner, Heather Lehr, and Becky Durost Fish. The History of the Democratic Party. Infobase Publishing, 2009.}

The 1840 Democratic-Republican national convention was also the one in which the party name was simplified. Henceforth, it was called the Democratic party.

_{- Goldman, Ralph Morris. The National Party Chairmen and Committees: Factionalism at the Top. ME Sharpe, 1990.}

Still others list the the official adoption of the Democratic Party name in 1844. However as far as I can tell there are no readily apparent evidence (e.g. cited resolution/proceedings) the back up these assertions.