Reading a little and thinking relegation and competition ... the US is developing into a hybrid of OUR Professional history (soon all franchises in MLS will be owned individually by solid deep pockets; then the USL starts to come around) and the Premier League models.
"... similar to EFL, the second tier USL will now be called the USL Championship, its third tier offering -- set to begin play in 2019 -- will be named USL League One, while the amateur Premier Development League will be renamed USL League Two. All three leagues will be contained under the USL organization.
"The USL has spent the past eight years transforming our league to meet the evolving needs of our team owners, players, coaches, fans and partners," said USL CEO Alec Papadakis via a prepared statement."
So ... you have this monstrosity of EXPAND manifest destiny in MLS which is a money grab. Then. Hartford and others (including affiliated teams for MLS) build their base, get financially stronger, FANS ... etc. I just found out that the project I have been kinda working in Baltimore - Westport - is targeted for a USL stadium. Hard to see - down the line - that they will keep Baltimore out of the Hartford level of leagues, considering the size of the GDP is #19 in the US Metropolitan rank.
Maybe this will work into something great. IF ... you do well at the USL level, MLS gives you the capacity to jump. The stadium in Baltimore discussion is modest (but exciting location); that could be the groundwork for something in the future.