"Could public opinion north of the Ohio River have been inflamed due to the Federal government being largely under control of Southern slaveholders and states rights in the North were being denied?"

Interesting. How do you feel that the federal Government was largely control by the southern slave holders?

The 11 southern states that eventually made up the Confederacy only repersented 56 of the 227 members of the US House of Repersentative in 1860 and only 22 of the 66 Senators in the US Senate. The States of New York, Pennsylvania and Ohio alone totally offset the total electorial votes of all 11 of the southern Confederacy States. Even if you consider the total repersentation of the 4 Border States of Missouri, Kentucky, Maryland and Delaware you are only talking about 24 repersentative and 8 senators who could have offset the huge advantage of repersentation in both house of Congress that the northern state held.

The advantage held by either side was not about geographical regions or even slave ownership. The parity, or control that you speak of, was based not on those such things, but upon political party affilictions, Democrats vs Whigs and Republicans. So it is a mistake to attribute the political power to only the Slave Holders because many Northern Democrats, which were the balance of power, were not slave owners and did not wish to be. It is the Nothern Democrats which are the "forgetten" element in all of this.