Final answer:
The 15th Amendment expanded citizenship rights by granting African American men the right to vote, marking a pivotal moment in the pursuit of equal suffrage in the United States. However, African American suffrage was not fully protected until the Voting Rights Act of 1965, and women had to wait until the 19th Amendment in 1920 for their suffrage.
Step-by-step explanation:
In the context of the United States' historical journey towards equality, the 15th Amendment played a crucial role in expanding citizenship rights by granting suffrage to African American men. Ratified in 1870, the 15th Amendment stated that the right to vote could not be denied based on race, color, or previous condition of servitude. Although it was a significant step forward, its impact was limited due to the emergence of discriminatory practices like literacy tests and poll taxes, which effectively disenfranchised many African American voters until the passage of the Voting Rights Act of 1965. Women, including those who fought alongside men during the abolitionist movement, did not gain the right to vote until the 19th Amendment was ratified in 1920.