Who won the battle union or confederatehow do you know who won?

The Union won the Civil War, which effectively ended with the surrender of the Confederate Army in April 1865. This victory is evidenced by the signing of the surrender documents by Confederate General Robert E. Lee at Appomattox Court House. Additionally, the Union's victory led to the preservation of the United States and significant changes in federal policies, including the abolition of slavery. Historical records, including military reports and subsequent legislative actions, confirm the Union's triumph.