On Septeber 16, 1782, the Great Seal of the United States of America was used for the first time. From the article:
"Many symbols have been used to represent the United States of America over the course of its nearly 250 year long history. None, however, have enjoyed the level of use and popularity equal to that of the Great Seal of the United States. Though rarely depicted in its entirety, the Great Seal of the United States has become so ubiquitous in that country, that few recognize it or are aware of its name. Yet it is nearly as old as the nation it symbolically represents, dating back to the time that country declared its independence."