I don't think it was Lincoln, his cabal or the Northern state militias who fired the first shots at Ft. Sumter. And the large numbers of southerners who served in the Union army should cast doubt on the framing of the Civil War as a war of North versus South.
And what is your point....that the first to fire was to blame?
Then, the Union troops at Ft. Barrancas take that honor.... a full three months before Sumter....January 8, 1861.
But if you want to focus on Ft. Sumter, the first shot was fired there by the Union Ship Harriet Lane, by Union Lieutenant Tompkins.
He was a part of the Lincoln Cabal military.