I’ve found some evidence of how the Anglo-Irish cleric George Berkeley’s verse, “Westward the course of empire takes its way,” became a “star of empire” on the cover of George Bancroft’s History of the United States. The connecting link seems to be John Quincy Adams, with an assist from Massachusetts poet Sarah Wentworth Morton.
George Berkeley (1685-1753) — the minister, mathematician, philosopher, Rhode Island planter, and namesake of Berkeley, California — was what we’d call a fan of Britain’s American colonies. So the last four lines of his “Verses on the Prospect of Planting Arts and Learning in America” were frequently quoted on this side of the Atlantic — especially the first:
Westward the course of empire takes its way;
The first four Acts already past,
A fifth shall close the Drama with the day;
Time’s noblest offspring is the last.