I didn't see it here, but I've both heard and read that the early Republican Party actually addressed "wage slavery" - can anyone confirm that?
yes, they basically denied the concept existed in that those who earned wages with the ability to do so were free to rise to level of their ability. From the very beginnings of the party, the Republicans espoused a strong belief in upward mobility. Arguably that was easier to achieve in the 19th century than in the 21st century. It was Southern Democrats who most strongly tried to equate wage earning with an imperfect form of slavery in which the old and disabled were left to fend for themselves once they were no longer useful to their masters while in the South old and infirm slaves were looked after by their masters in a glorious form of Christian socialism.
The 1850s Republican ideal of "free labor" meant independent farmers, craftsmen, artisans, and other self-employed business people. Wage labor was thought of as a temporary condition for the upwardly mobile working man. Of course, by the late 1800s there was nothing temporary about it for vast numbers of people.