IMO a wonderful day that is well worth celebrating.
For those who don't know the history, here is one source that sums it up in a nutshell:
nmaahc.si.edu
For those who don't know the history, here is one source that sums it up in a nutshell:

The Historical Legacy of Juneteenth
Juneteenth is an often overlooked event in our nation’s history. On June 19, 1865, Union troops freed enslaved African Americans in Galveston Bay and across Texas some two and a half years after President Abraham Lincoln signed the Emancipation Proclamation.