How won the war of antietam in September 1862?

ill give brainliest

It was the union side that won

he Battle of Antietam is considered the bloodiest day in the history of American war, with over 23,000 soldiers wounded, killed, or missing. The Union held off the invasion of the Confederacy, although President Abraham Lincoln was very unhappy that the Confederates were allowed to retreat back to Virginia. Still, the battle was declared a Union victory and Lincoln followed it with the Emancipation Proclamation, which officially made slavery the primary cause of the war.

but from what i know the Union won

The Union victory also kept France and Great Britain from recognizing the Confederate States of America as an independent nation and providing aid to the South. They were close to doing so because they wanted to resume importing southern cotton.