Righteousness Exalts a Nation (Proverbs 14:34)

Righteousness exalts a nation, but sin is a reproach to any people. - Proverbs 14:34
Starting with Proverbs 10, a long chain of proverbs contrast the wise and the foolish, the righteous and the wicked, poor and rich, good and evil. But this one is somewhat unique in that it speaks not of the individual, but of a nation, a tribe, an ethnic group, any people group. As Americans celebrate 245 years as a nation on July 4, this proverb definitely applies. Is the United States of America characterized by national righteousness? What sin is a reproach to our country? How does the church and individual believers contribute to the direction of our nation?