Several battles were had in Arkansas during the Civil War. The Heritage Preservation Services offers summaries of battles on an interactive map. http://www.nps.gov/hps/abpp/battles/ARmap.htm
If you mean which American Civil War battle then it was the Battle of Gettysburg which took place July 1st - July 3rd of 1863.
The Battle of Shiloh, also called the Battle of Pittsburg Landing, occurred in Southwestern Tennessee, in Hardin County.
That would have been the battle at Gettysburg.
The first naval battle of the Civil War happened on April 13, 1861. This naval battle took place at Fort Sumter.
Fort Sumter
This US Civil War battle took place in Arkansas on July 4, 1863. It was a Union victory that secured eastern Arkansas for the Union.
The US Civil War Battle of Prairie Grove took place in Arkansas on December 7, 1862. It was a Union victory and it secured northwest Arkansas for the North.
The US Civil War battle of Bayou Fourche took place in Arkansas on September 10, 1863. It was a Union victory and led to the capture of Little Rock, Arkansas.
The Battle of Poison Spring was a Confederate victory. The battle took place in Arkansas on April 18, 1864. Union forces attempting to secure total control of Arkansas were defeated.
There were two battles by that name, one in Arkansas the other in Texas.
The Battle of Pea Ridge, also known as the Battle of Elkhorn Tavern, was the largest Civil War battle fought west of the Mississippi River in 1862. It took place in Arkansas and was a key Union victory that helped secure control of Missouri and the Mississippi River.
The 1862 Civil War battle known as the Battle of Antietam (or the Battle of Sharpsburg) took place near Sharpsburg, Maryland, and around Antietam Creek. This area is found in northwestern Maryland, approximately 60 miles from Washington, D.C.
Benton County, Arkansas
The battle of Bunker Hill was a pretty big civil war battle that took place in Gettysburg
The largest civil war battle in Florida took place at Olustee. It was called the Battle of Olustee and was fought on February 20, 1864.
The battle of Chancellorsville :-)
The Civil War battle that did not take place along a body of water was the Battle of Perryville. This took place on Chaplin Hills on October 8, 1862.?æ