Which agency was established to aid former slaves in adjusting to freedom after the Civil War?

The Freedmen's Bureau was established in March 1865, during the final months of the Civil War, specifically to assist formerly enslaved individuals in transitioning to freedom. This agency played a critical role in providing various forms of support, including education, housing, healthcare, and legal aid, to help former slaves integrate into society after the abolition of slavery.

Its efforts were aimed at addressing the immediate needs of freed individuals in the South, particularly in the wake of the devastation caused by the War. The Bureau also sought to assist poor whites who were in dire conditions due to the economic disruptions following the conflict. Through establishing schools, providing food, and facilitating employment opportunities, the Freedmen's Bureau became a pivotal institution in the Reconstruction era, helping shape the social fabric of the post-war South.

In contrast, the other mentioned options, such as the American Reconstruction Agency, Southern Relief Fund, and Union Assistance Office, do not correspond to any historically recognized organizations established for aiding former slaves, making those choices less relevant in this context. The Freedmen's Bureau remains the primary agency synonymous with this mission.