The phrase "manifest destiny" is most often associated with the territorial expansion of the United States from 1812<span> to </span>1860<span>. This era, from the end of the War of </span>1812<span> to the beginning of the American Civil War, has been called the "age of manifest destiny".</span>
The Gulf of Tonkin Resolution happened during Vietnam War, so the headline of the paper could only be during the Vietnam War.