The Equal Protection Clause was originally intended to protect African Americans.
Before the Clause was passed, as part of the Fourteenth Amendment (1868), black people were the main group who had been suffering from discrimination. They were considered inferior socially and legally. It wasn't until the Thirteenth Amendment was passed, that became illegal to own them as slaves, still they suffered from the misfortunes of not being considered equal.
The Clause was an attempt to grant them equal rights by guarantying that no person or group will be denied the protection under the law. As it states:
"All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws."
