In the timeline I am working on, the US severely loses the war of 1812. The loss of territory in the north leads them to instead look to the south for expansion, kind of like in Decades of Darkness. An alternate Mexican-American war see's the establishment of an independent Sonora Republic and Rio Grande as US client states and the cession of Yucatan. Following these wars, America begins to expand it's influence into Central America.
What I'm wondering is if following the US conquests in Central America, would the US simply establish these nations as clients, or might they unite them [reviving the former Federal Republic of Central America 1823-1839] for administrative purposes?