Question – Did the Central Figures and Shoghi Effendi preached against racism, and proclaimed that all races are equal in every respect?

Neither The Bab nor Baha’u’llah mentioned anything about the oppressions against the Blacks. They had black slaves. They did NOT write that races are “equal”.
Abdu’l-Baha did NOT say that the races were equal, but that the Persian race was the most intelligent at birth.
Shoghi Effendi NOWHERE wrote or said that the races are equal in intelligence. He did NOT condemn scientific racism (something he was taught at Oxford as scientifically proven fact), but rather “racialism”; the philosophy that one race can dominate others.