The question of who fired the first shot of the Civil War is murky; Edmund Ruffin, a longtime proponent of secession, is generally given credit for firing the first shot at Fort Sumter at 4:30 in the morning of April 12, 1861, but a signal shot had been fired at Sumter before Ruffin that same morning by Lieutenant Henry S. Farley. One also could argue that the shots fired by Citadel cadets at the Star of the West back on January 9, 1861 when it tried to run supplies into Fort Sumter were the opening shots of the war. Civil War historiography is replete with references to some unit or individual firing the first shot of a battle; at Gettysburg, there is even a monument to the first shot, erected by three soldiers from the 8th Illinois Cavalry on the Chambersburg Pike three miles west of town.
But who fired the first shot in the western theater? This fact also seems rather murky, at least at first glance. A Google search returns no claims from anyone stating they fired the first shot. Maybe with the war already raging in the east, nobody noticed or cared about the first shots of the war in the west. We do know that the first engagement of any significance took place June 17, 1861 at Booneville, Missouri where 1,700 Federals under Nathaniel Lyon mixed it up with about 1,500 Missourians under John Marmaduke with fairly light casualties on both sides. One could argue that the first shots fired in the western theater may have occurred during the Camp Jackson affair on May 10, 1861 in St. Louis, Missouri, which amounted to a riot similar to the Pratt Street Massacre that occurred in Baltimore, Maryland a few weeks before.
It turns out the first shot actually predates the Camp Jackson affair and occurred not in Missouri, but in neighboring Illinois. On April 15, 1861, President Lincoln issued his proclamation calling upon the nation to provide 75,000 volunteers to form an army to suppress the Southern rebellion. Lincoln’s proclamation posed a challenge for the eight slave states that were still in the Union; soon, four of those states (Virginia, Tennessee, Arkansas, and North Carolina) would secede, throwing their lot in with the Confederacy. It is important to note that the Mississippi River was the primary path of commerce for both the Midwest and the Deep South, including states like Mississippi and Louisiana which had seceded prior to Fort Sumter. As such, there was a boat traffic on the Mississippi that could potentially be hauling war material to the South. The War Department wanted that trade broken up, and fast.
That said, control of the Mississippi was an important war objective for both sides right from the outset, and for Illinois, there was no more strategic point than the river town of Cairo, Illinois. Located at the southern apex of the state, Cairo sat at the confluence of the Ohio and Mississippi rivers; as such, any force which occupied the town could control river traffic by planting batteries along both rivers. “The city of Cairo had a broad levee front on the Ohio River raised about 14 feet above the natural level of the city and extending for a distance of about three miles immediately along the river,” wrote one Federal engineer. “On the Mississippi side extends a levee of the same height and about the same length but removed from the bank of the river from 100 yards to a half mile distant. From this levee, across from the Ohio River, extends a levee the same height by which the town is protected from the backwater, the whole forming a delta These levees would afford admirable defenses upon which to plant batteries at proper points. The great Central Railroad of Illinois, in addition to the Ohio and Mississippi afford means of supplying this point with great rapidity with troops, munitions of war, and provisions.” 
Governor Richard Yates was well aware of Cairo’s strategic value, and with war now an apparent fact, he was also aware of how vulnerable it was. Secretary of War Simon Cameron telegraphed Yates to send troops to hold Cairo on April 19th, and Yates moved quickly to fortify the town. Trained troops were not available, so Yates turned to some of the militia companies that were coming into service, specifically he turned to the Chicago militia under General Richard Kellogg Swift. “As quick as possible, have as strong a force as you can raise armed and equipped with ammunition and accoutrements ready to march at a moment’s warning,” Yates telegraphed after receiving Cameron’s directive.
Swift went right to work and within hours had gathered five companies of infantry totaling 446 men along with the Chicago Light Artillery, 130 men manning four 6-pdr guns under Captain James Smith. His infantry companies included Co. A of the Chicago Zouaves under Captain James R. Hayden, Co. B of the Chicago Zouaves under Captain John R. Clybourn, the Chicago Light Infantry under Captain Frederick Harding, the Turner Union Cadets under Captain Kowald, and the Lincoln Rifles under Captain Geza Mihalotzy. “In spite of the efforts of citizens and friends, these companies left the city in poor shape for active service. No arms could be procured except as what could be hastily gathered from stores and shops in Chicago,” one historian wrote. “The battery was only provided with slugs and a small quantity of canister manufactured for the emergency by Miller Brothers, hardware merchants on State Street.” 
The Chicagoans departed the city on April 21st aboard the Illinois Central Railroad and made a beeline for Cairo, arriving the following morning. Along the way, General Swift dropped off one section of the battery and a company of Zouaves under Captain Harding at Big Muddy Bridge about 60 miles north of Cairo. Once in Cairo, the men set up camp, and went right to work throwing up entrenchments, and policing steamboat traffic on the Mississippi and Ohio rivers. The steamboat Swallow was armed with one gun and given guard duty. “Our camp is formed on the flat within the broad and long levees, which form an excellent breastwork,” wrote one of the Chicago volunteers. “The scene is warlike- batteries command the rivers; artillery horses are feeding in rows with their equipment hanging over the fences, tents are being raised, boxes, camp chests, baggage, blankets, and provisions are scattered about in huge piles. We men feel the difference between war and peace, the soldier and the civilian. We are all ready for the scratch.”
Yates wasn’t about to leave the defense of Cairo in the hands of a neophyte militia general, so he gave overall command of this scratch force to Benjamin Mayberry Prentiss, soon to be appointed colonel of the 10th Illinois Volunteers. The 41-year-old Virginia-born attorney from Quincy had previously served as a militia officer during the Mormon troubles in Illinois, then was a captain in the Mexican War with the 1st Illinois. His men may be green as gourds, but Prentiss had as much experience as any other officer at hand, so he drew the ticklish assignment at Cairo. Prentiss’ orders were simple: he was to halt all downbound steamers and inspect their cargoes for contraband of war. Anything found in the way of arms or equipment was to be seized.
Colonel Prentiss arrived at Cairo on the morning of April 24th with three companies of his 10th Illinois in tow, two of them artillery companies eager to take their posts on the levees: Captain Charles Houghtaling’s Ottawa Artillery [Co. F] , Captain Hawley’s Plainfield Artillery [Co. K], and Captain Lindsey H. Carr’s infantry company [Co. C] from Sandwich. Additional companies from the 8th and 10th Illinois regiments arrived in the coming days, swelling the garrison at Cairo to well over 1,000 men.
It didn’t take long for the Illinoisans to see an opportunity for service. That afternoon [April 24th], the steamer Baltic came into view downbound on the Mississippi. “There was a rumor that a steamer was expected up the river and that she would bring secession troops. At about 2 p.m., she was seen coming, her decks seemingly crowded. Major Baldwin directed a shot across her bow. Of this, she took no notice, but steamed on. There were our troops in sight and our colors flying and it appeared to us that she was determined upon an invasion. Major Baldwin mounted a platform car and waved for them to come to, several officers doing the same. But of this she took no notice, but proceeded toward her wharf above. The call was sounded and in less than four minutes the infantry was formed and came in ranks upon the run promptly led by Captain Joseph R. Scott , the Flying Artillery thundered along the levee and the whole force was ready in line at the wharf to meet any invasion. However, no enemy showed himself and we marched back, mad at the disappointment. But the scene for a moment was warlike.” 
So, who fired that first shot? It was the first squad of Battery A of the 1st Illinois Light Artillery under the command of Third Lieutenant John R. Botsford of Chicago according to the Illinois Adjutant General’s report. “On our arrival at Cairo, we were assigned the duty of bringing to all downbound boats with a view of preventing the shipment of contraband goods within the Rebel lines. The mode adopted for bringing boats to was to fire a blank shot in their direction. On the 24th of April, the steamer Baltic in passing Cairo disregarded the blank shot when a solid shot was fired across her bow, which had the desired effect. These shots were fired by squad one under the command of Lieutenant J.R. Botsford, and they were the first that were fired across this mighty river.” 
Who was Lieutenant Botsford? Prior to the war, he worked at Botsford, Kimball & Co. as junior partner, a firm located on Lake Street in Chicago that specialized in importing English cutlery, flatware, and hardware. Born in 1836, Botsford’s service with the Chicago Light Artillery at the outset of the war predated its mustering into service; Botsford didn’t go off to war with Battery A and apparently returned to Chicago shortly after the events at Cairo. That said, Botsford isn’t listed on the rosters of Battery A and a search of Civil War records found no other war service for the Chicagoan. He died at the age of 43 in 1880 and is buried at Rosehill Cemetery in Chicago.
The Baltic was only the first brush; soon the steamers C.E. Helmick and John D. Perry, downbound from St. Louis, hove into sight and were seized by Prentiss’ troops. The Helmick, bound for New Orleans, was found carrying “large amounts of powder, lead, shot, and other munitions of war. Her officers, passengers and crew deserted her in great haste,” it was reported. A search of the Perry yielded nothing and the vessel was sent on its way. 
The seizures continued and on Friday April 26th, a real prize was found when a vessel failed to heed the shot across the bow, and ran ashore on the Kentucky side. “We took from this boat bound for the South 5,000 Sharp’s rifles, 10,000 Colt’s revolvers, a very large quantity of powder, a large amount of 50-lb lead bars, and all kinds of munitions and clothes comprising caps, coats, pants, drawers, shirts, boots, shoes, and socks,” reported Homer H. Kidder of the 8th Illinois. “The boat would not come to shore so we turned our cannon towards when she made over to the Kentucky side and put a slow match to the powder on board, then all left the boat. We succeeded in reaching the boat before the match communicated with the powder. The prize was worth $600,000 and we expect tomorrow to be armed with the Sharps’ rifle and a pair of Colt revolvers.” A Chicago volunteer was delighted to receive “ a lot of beautiful red, blue, and grey military caps” from this seizure. “These came very convenient and today each of us sport a “secession” cap. If they only keep sending us supplies this way, it will be a great relief to the Quartermaster’s department.”
And so it was that the war in the western theater began around 2 p.m. on April 24, 1861 at Cairo, Illinois when gunners under the command of Third Lieutenant John R. Botsford of Chicago Light Artillery opened fire with a 6-pdr cannon on the steamboat Baltic. The Mississippi River would flow in its “vexed” state for more than two years, a scene of tremendous clashes between ironclads, rams, and armies before another Illinoisan, General Ulysses S. Grant, would successfully lead a campaign to reopen the river by taking Vicksburg.
 Fowler, William M., Jr. Under Two Flags: The American Navy in the Civil War. Annapolis: Blue Jacket Books, 1990, pg. 131  Andreas, Alfred T. History of Chicago from the Earliest Period to the Present Time. Volume II: from 1857 until the Fire of 1871. Chicago: A.T. Andreas Co., 1885, pg. 163  Letter from “Cortos,” Battery A, 1st Illinois Light Artillery, Chicago Tribune (Illinois), April 26, 1861, pg. 1  Warner, Ezra J. Generals in Blue: Lives of the Union Commanders. Baton Rouge: Louisiana State University Press, 1964, pgs. 385-86  He became Colonel Scott of the 19th Illinois Infantry and was killed in action January 2, 1863 while leading a charge across Stones River.  “Cortos,” Ibid.  Adjutant General’s report of the State of Illinois for Battery A, 1st Illinois Light Artillery; https://civilwar.illinoisgenweb.org/history/a-001-lt.html; retrieved July 4, 2021; see also Andreas, Alfred T. History of Chicago Volume I. New York: Arno Press, 1975, pg. 285  Find-A-Grave record for John R. Botsford; https://www.findagrave.com/memorial/139685448/john-r.-botsford; retrieved July 5, 2021  “From Cairo: Another Steamer Stopped-More Munitions of War Seized,” Chicago Tribune (Illinois), April 27, 1861, pg. 1  “From the Cairo Boys,” Chicago Tribune (Illinois), April 27, 1861, pg. 1  Letter from Private Homer H. Kidder, Co. H, 8th Illinois Volunteer Infantry, Hillsdale Standard (Michigan), May 21, 1861, pg. 2  “From the Camp at Cairo,” Ottawa Free Trader (Illinois), May 4, 1861, pg. 2