Kate Masur's Until Justice Be Done not only provides an exceptionally important and timely contribution to nineteenth-century American historiography but also supplies readers with a broader, deeper understanding of the history of racial ideas and practices in the United States. Her deeply researched, vividly told story of Black and white Americans’ courageous struggle to realize the ideals proclaimed in the Declaration of Independence can be both inspiring and discouraging. Building on the work of generations of scholars, Masur investigates the ways white people's prejudices throughout the nation created customs and laws that discriminated powerfully against free African Americans while concurrently securing slavery in states where white voters chose to maintain the not-so-peculiar institution. Masur shows us how growing numbers of activists pushed against this rising tide of white supremacy, convincing increasing numbers of voters to support equal civil rights. Ultimately, their efforts would carry the free soil Republican party into Congress and the White House. There, while they controlled the levers of power, Republicans transformed the Constitution, abolishing slavery and proclaiming birthright citizenship nationwide.But as Masur explains in her epilogue, although Radical Republican politicians could deal white supremacy a setback, they could not defeat it. When former Confederate states rejoined the Union, resurgent white supremacists took advantage of custom, ideology, and law to render the Fourteenth and Fifteenth Amendments void in many states and as national policy. Non-enforcement of the Civil Rights Act of 1875, which barred discrimination in some public accommodations, together with the Supreme Court's 1896 proclamation of the “separate but equal” doctrine in Plessy v. Ferguson, ensured white supremacy's longevity.Masur's fresh research supplies a narrative and an analysis of civil rights activists’ efforts to erase discriminatory laws restricting free Blacks’ movement, their eligibility to testify in court, and other civil (as opposed to political) rights. Activists’ goal was to win recognition of free Black citizenship, state and national. Much of Until Justice Be Done treats the Midwest, with chapters dedicated to political battles in Ohio and Illinois. In those states, as in Indiana, Michigan, and Iowa, Masur shows that though the Northwest Ordinance excluded slavery, white settlers’ biases against African Americans and white readiness to regulate the activities of free Blacks were widespread beyond the South—in the west and throughout the United States. The unpleasant truth was that new states welcomed white immigrants while restricting, when they did not actually ban, free Black settlement. As Masur explains, the Constitution's Article Four, which seemingly required each state to recognize the equal citizenship rights (the “privileges and immunities”) of citizens from other states, could never be enforced. Asserting the authority of their “police powers,” most states claimed the right to regulate and even to imprison or enslave free African Americans who entered their jurisdiction. Although Massachusetts and New York leaders protested in Congress—eager to protect their sailors of color—the national government, including the US Supreme Court, recognized states’ constitutional claims, deferring to discriminatory state policies.Over time, Ohio's abolitionists and Free Soilers succeeded in overturning most of their state's Black laws and, following passage of the 1850 Fugitive Slave Act, nationally abolitionists and their allies would mount a powerful drive against discriminatory legislation. By the 1850s, Masur explains, the free states of Oregon, Iowa, and Indiana all excluded free Black settlers, with the latter reinforcing its ban with a specific provision in its 1848 constitution. Neighboring Illinois enacted Logan's Law in 1853, prohibiting anyone from bringing any African Americans, free or slave, into the state. But this law, like the Fugitive Slave Act, mobilized opposition to what abolitionists had been calling the “Slave Power.” Ultimately, the Republican Party emerged as a northern political response. When Republicans took power, winning a plurality of the House of Representatives in 1858 and gaining the Presidency in 1861, secession by eleven of the fifteen slave states handed opponents of slavery control of the entire national government. In 1862, the Republican dominated Congress enacted a long-sought abolition goal by ending slavery in the District of Columbia. In the same year they passed the Homestead Act, which effectively recognized African American citizenship by providing public lands to Black as well as white settlers. As Masur explains, the decades of agitation and advocacy by Black and white activists at last bore fruit, now that their allies, not slaveholders, shaped policy.As one would expect, Masur treats Radical Republicans’ Congressional leadership as the climax of this first civil rights movement. Now, for the first time, the 1868 Fourteenth Amendment explicitly proclaimed national birthright citizenship, specifically barring states from denying equal protection to all citizens (African Americans) and persons (Chinese immigrants). In addition, by expressly empowering Congress to override state obstruction, the amendment reversed the pre-war ruling that the Constitution made states’ “police powers” pre-eminent.Because Masur focuses on civil, not political rights, she can side-step the fraught battle over women's suffrage, treating the enfranchisement of Black men in the Fifteenth Amendment only briefly. However, she points out that enabling Black men to vote was critical for the Republicans and civil rights because the abolition of slavery had increased southern states’ representation in the House of Representatives. Whereas before the Civil War, whites’ representation of enslaved people magnified their number of House seats by sixty percent (three-fifths), after abolition whites dramatically increased their representation by preventing Black men from voting. For that reason, among others, the Compromise of 1877, the withdrawal of US troops, and the national failure to enforce the Civil Rights Act combined to all but eliminate black voters, defeating Radical Republicans’ aims.Though every civil rights advance of previous decades was not reversed, many were. National recognition of a revived states’ rights doctrine, manifest in “separate but equal,” would assure policies of white supremacy for generations. By giving legitimacy to segregation in education, employment, housing, and public accommodations, supremacist policies nearly erased the bravery, idealism, and accomplishments of the first civil rights movement that Kate Masur so insightfully chronicles. Segregation masquerading as “separate but equal” rights supplied legitimacy for race discrimination. After Plessy, though new generations of activists opposed segregation in the United States Post Office and the United States armed forces, no congress and no president would challenge segregation until confronted by comparison with the Nazi regime.