What do each of the following three parts mean? "The slave went free; stood for a brief moment in the sun; then moved back again toward slavery."

In tracing the development of Black consciousness in America, DuBois focuses on the period of slavery, which helped to create the stigma or problem of "color," the Civil War with Abolitionists and Lincoln, and the challenges of Reconstruction.  With the ending of the Civil War, the North's victory, and the official end to the institution of slavery in the South, the "slave went free."  Slavery was over and there was a feeling of freedom being present.  This represented "a brief moment in the sun."  The establishment of the Freedman's Bureau helped to "make the Negro a ward of the nation."  Noting its successes in the South, in particular educational opportunities and the expansion of health care and other government services, this would be the moment where the sun' moment was felt.  The brevity or shortness of this moment was valid and real as there was no political power for people of color (14th Amendment not yet passed), social inequality still continued in that many Southern Whites were not willing nor comfortable with full social recognition of African- Americans, and this translated to a lack of economic empowerment opportunities.  Both of these components- the lack of a political and economic voice- represented the "move back again towards slavery."  The quotation reflects the complexity in achieving a valid conception of freedom, a complexity that was manipulated to ensnare African- Americans in the wake of the Civil War.