By United_States_1861-01-1861-02-04.png: Made by User:Golbez.derivative work: Kenmayer (talk) - United_States_1861-01-1861-02-04.png, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=11784865

A timeline on the War Between the States and the issue of slavery:

The War is popularly dated to have begun on April 12th, 1861.

The Emancipation Proclamation was not issued by Lincoln until January 1, 1863.

Maryland, a Union state, did not end slavery until the adoption of a new State Constitution on November 1st, 1864.

Missouri, which never officially seceeded from the Union, abolished slavery by statute on January 11, 1865.

On April 9, 1865, near Appomattox Court House, Virginia, Confederate General Robert E. Lee surrendered his Army of Northern Virginia to Union General Ulysses S. Grant.

Delaware, a Union state, rejected the 13th and 14th Amendments, and slavery ended there only when the 13th Amendment took effect nationally in December, 1865.

Kentucky, which never officially seceeded from the Union, rejected the 13th Amendment, and slavery ended there only when it took effect nationally in December, 1865.

The War Between the States was never about slavery, and this simple timeline should be proof enough of that.