How was western expansion apart of the "Era of Good Feelings"?

The "Era of Good Feelings" was a time period that lasted from 1817 to 1825. This era in the US reflected the unity, purpose and high moral of all Americans after end of the war of 1812.

It was an era where the Democratic-Republicans split into two parties; The northern-dominated Republicans and the southern-dominated Democrats and because both parties were originally a single one it led to are more stable government with very few political quarrels.

As such President James Monroe (1817-1825) saw as only natural to expand the national power of the United States and so it turned to the west to expand on the vast lands and resources this region had, this was due in part to the Louisiana Purchase in 1803. This expansionism took advantage of the high morale after winning The war of 1812 and The Second Barbary War of 1815.