Rocky ocean cliffs and tangles of green foliage. Crowded Edgartown restaurants, large yachts, and even larger gray-shingle mansions. These are the images that many people equate with Martha’s Vineyard.

What is less known is that the island has a long-enduring African-American history as well.

President Obama, who arrived Sunday on Martha’s Vineyard with his family for a week-long vacation, is helping to highlight that history.