Amasa Sprague assumed leadership of his family's business following his father's death, successfully managing and expanding operations. He completed a significant cotton mill construction project and experienced substantial business growth during the Civil War. Despite achieving remarkable output and profits in the early 1870s, his company eventually fell into receivership due to poor investments. Sprague transitioned into public service, representing his district in the state legislature and later serving as sheriff. He also made notable contributions to the horse racing industry, founding a prominent racing park and leading a national association.

Amasa Sprague's political identity is marked by a unique blend of business acumen and regional advocacy. His early success in managing a thriving cotton mill during the Civil War and subsequent financial setbacks reveal a highly localized approach to economic policy. Sprague's switch from the Democratic to the Republican Party in 1890 suggests an ideological flexibility that challenges standard partisan affiliations. His involvement in horse racing and the founding of Narragansett Park indicate a surprising intersection of leisure interests with political influence.