Final answer:
Ernest R. Breech was the first African-American to serve on the Board of Directors of General Motors.
Step-by-step explanation:
The first African-American to serve on the Board of Directors of General Motors was Ernest R. Breech. Breech joined General Motors in 1941 and became a member of the Board of Directors in 1946. He played a significant role in turning around the company's financial performance during his tenure.