Actor Matthew McConaughey marked the historic anniversary with a stirring speech describing the United States not merely as a country, but as an idea that remains worth defending.

McConaughey said America was founded on faith that a self-governing people could build something worthwhile, and that 250 years later, the nation’s great experiment continues.

He drew a sharp distinction between skeptics, who care enough to question the country, and cynics who have already abandoned it.