Change each compound or complex sentence below into a pair of shorter sentences. Use correct punctuation. You may add words if necessary. More than that, it infused the nation with a commitment to far horizons and new frontiers, and thereby kept the pioneer spirit of American life, the spirit of equality and of hope, always alive and strong.
But the very problems of adjustment and assimilation presented a challenge to the American idea—a challenge which subjected that idea to stern testing and eventually brought out the best qualities in American society.