The statement that best assesses the gains and setbacks of Black Americans during Reconstruction is: "While Black Americans were granted rights, states like Texas made it difficult for them to exercise those rights."
This choice accurately reflects the dual nature of Reconstruction; while constitutional amendments and laws were intended to secure rights for Black Americans, Southern states implemented various policies and practices, such as Jim Crow laws and voter suppression tactics, that undermined those rights and created significant barriers to their exercise.