Final answer:
The 14th Amendment is the most referenced concerning affirmative action as it guarantees equal protection under the law to all citizens.
Step-by-step explanation:
The amendment most referenced concerning affirmative action is the 14th Amendment to the United States Constitution. The 14th Amendment, which was passed by the Reconstruction Congress in the late 1860s, guarantees equal protection under the law to all citizens. This amendment has become the centerpiece of civil rights legislation and has been used to support affirmative action as a means to ensure equal opportunity for historically disadvantaged or underrepresented groups.