AHC/WI: Republic of Maryland


Your challenge, with a POD after its creation IOTL on May 29th 1854, is to have the Republic of Maryland remain an independent sovereign state to the present day. How could this be brought about? Also, if this were to happen, how much of an impact would it have- would it change anything, on a regional, continental or a world scale? And if so, how much?
It fell apart due to disrupting the slave trade and being invaded by local tribes, and then decided it wouldn't last on its own. Good God, it's the nation we cannot save!
An earlier end to US slavery and more dedicated black repatriation effort might be a good starting POD. Maryland could become one of several former slave states that would be strengthened by the influx of black people from the US. IIRC the Republic of Maryland came under attack from native African tribes, and eventually had to ask Liberia to send military assistance. The campaign against the tribes was successful, but there appeared no future for Maryland, and thus a referendum was held in which all participants favored union with Liberia.