Complex sentence: Chase articulated the "Slave Power conspiracy" thesis well before Lincoln, devoting his energies to the destruction of what he considered the Slave Power the conspiracy of Southern slave owners to seize control of the federal government and block the progress of liberty.
Split into simpler sentences: Chase articulated the "Slave Power conspiracy" thesis well before Lincoln. He devoted his energies to the destruction of what he considered the Slave Power the conspiracy of Southern slave owners to seize control of the federal government and block the progress of liberty.