From September 15 to October 15, Americans observe National Hispanic Heritage Month, a time to celebrate the heritage, history, traditions, and cultural diversity of Hispanic Americans whose heritage is rooted in Spain and 19 countries and territories: Mexico, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, Panama, Colombia, Venezuela, Ecuador, Peru, Bolivia, Paraguay, Chile, Argentina, Uruguay, Cuba, Puerto Rico, and the Dominican Republic.

This heritage month is celebrated mid-September to mid-October to highlight the independence of several countries. September 15 is the day that five Latin American countries celebrate their independence from Spain: Costa Rica, El Salvador, Nicaragua, Guatemala, and Honduras. Mexico celebrates its independence on September 16 and Chile on September 18. Also, Columbus Day/Indigenous Peoples Day, or Día de la Raza, in mid-October, falls within this 30-day period.

The national observation began in 1968 as Hispanic Heritage Week under President Lyndon Johnson and was expanded by President Ronald Reagan in 1988 to cover a 30-day period starting September 15 and ending October 15 of each year. It was enacted into law on August 17, 1988, on the approval of Public Law 100-402. Each year the President of the United States has issued a proclamation at the start of the observance.

Each year, the NCHEPM has lead the process to select the annual theme and corresponding poster that federal agencies, organizations, and schools have used when observing Hispanic Heritage Month.