Juneteenth: From local celebration to federal holiday

The United States will observe Juneteenth on Thursday, a federal holiday that commemorates the anniversary of when Union troops arrived in Galveston Bay, Texas, and announced that the enslaved population was free.
Union General Gordon Granger and his men arrived at the Texas city with their announcement about two months after Confederate General Robert E. Lee had surrendered at Appomattox Courthouse in Virginia.
Also called Freedom Day or Jubilee Day, Juneteenth is generally recognized as the longest-running African American-centered holiday in the country, having been first observed in 1866.
The journey from local observance to national holiday was a lengthy one, spanning over a century-and-a-half of American history. Here are some highlights of that journey.