Lincoln's Historic Emancipation Proclamation freed all slaves on Jan 1, 1863; that's the day they should be celebrating, instead of this idiotic -- yes, I know about the Union Army in TX etc -- date.
The Emancipation Proclamation only freed slaves in the rebelling states it took the 13th Amendment to free them in places like Delaware, Maryland, etc. That Amendment or the whole set of Reconstruction Amendments (13th - 15th Amendments) is what should be celebrated not some minor event in Texas. (minor to the rest of the country, maybe significant to Texas!) All this shows is ignorance, as well as English illiteracy!
This is simply not true. The Emancipation Proclamation freed the slaves in states that were in active rebellion against the Union. Slaves in Union states were enslaved until the ratification of the 13th Amendment on December 6, 1865. The Emancipation Proclamation itself, excluded many areas in the South.
Here is the text of the Emancipation Proclamation.
https://www.archives.gov/exhibits/featured-documents/emancipation-proclamation/transcript.html