How does Phillis Wheatley personify the American colonies in "To His Excellency General Washington"?

In Phillis Wheatley's homage to George Washington, commander of the Continental Army, the poet creates a goddess she calls Columbia to personify the American colonies. The goddess wears olive and laurel to symbolize peace and victory and inspires admiration—and fear—in those who would oppose her. Wheatley refers to Eolus, the Greek god of the winds, as a peer of Columbia's, but the goddess was Phillis Wheatley's creation.  

The line "Columbia's scenes of glorious toils I write" refers to the state of the colonies when she wrote the poem and sent it to George Washington in October 1776. The outcome of the Revolutionary War would not be known for another seven years. Wheatley's poem was meant to honor Washington and encourage him to continue to lead "Columbia" to victory.