Which Constitutional Amendment defines citizenship and includes due process and equal protection under the law?

The 14th Amendment to the United States Constitution is significant for its definitions and protections concerning citizenship. It establishes that all persons born or naturalized in the United States are citizens, thereby confirming the principle of birthright citizenship. Furthermore, the amendment includes critical clauses related to due process and equal protection under the law, which ensure that states cannot deny any person within their jurisdiction the equal protection of the laws. This amendment was ratified in the aftermath of the Civil War and was aimed at addressing the rights of former slaves, making it a cornerstone of civil rights in America. In contrast, the other amendments listed do not specifically define citizenship or include these protections. The 13th Amendment abolished slavery, the 15th Amendment granted voting rights regardless of race, and the 9th Amendment addresses unenumerated rights but does not discuss citizenship directly.