original_query: What is the significance of U.B. Phillips in American history?
query: What is the significance of Ulrich Bonnell Phillips's contributions to American history?
answer: Ulrich Bonnell Phillips was a highly influential historian of the antebellum American South and slavery, whose work, though later criticized for its biases, shaped the research agenda of subsequent scholars. His focus on the economics and social structure of slavery, combined with his eloquent writing style, made him the most influential historian of the antebellum South in the 20th century.  However, his favorable portrayal of slave owners and his views have been challenged and revised over time.