The significance of the Fourteenth Amendment, ratified in 1868, lies in its foundational role in defining citizenship and protecting civil rights in the United States. It grants citizenship to all persons born or naturalized in the country and ensures that states cannot deny any person equal protection under the law or "deprive any person of life, liberty, or property without due process." The Amendment has been pivotal in numerous landmark Supreme Court cases, addressing issues such as racial segregation, voting rights, and marriage equality. Its broad implications have made it a crucial instrument in the ongoing struggle for civil rights and justice in America.