Answer:
this was for expressing gratitude for a pivotal union army victory at gettysburg on october 3, 1863, President Abraham Lincoln announces that the nation will celebrate an official Thanksgiving holiday on November 26th, 1863 he also said I do therefore invite my fellow citizens in every part of the United States to set apart and observe the last Thursday of November next as the day of Thanksgiving.
Explanation:
I said above I hope this helps
