The Western Sharpshooters (under three official titles: "Birge's WSS"; "WSS-14th Missouri Volunteers"; and "66th Illinois Veteran Volunteer Infantry [Western Sharpshooters]) were arguably the premier Federal unit in the Western Theater. (They were almost certainly the most lethal.) Unfortunately, after the war's end the official history published by the Adjutant General of Illinois deemphasized the Regiment's mutli-state origins, effectively deleting it from (most of) history.

Intended as the Western Theater's counterpart to "Berdan's" 1st & 2nd U.S. Volunteer Sharpshooters. They were recruited on Major General (MG) Fremont's orders in Aug-Nov 1861 as the "Western Sharpshooters" to represent "All the States of the West". Perspective members required to shoot from a standing position, and place10 shots in a 3 inch group at 200 yards. Prospective members and companies assembled at Benton Barracks, St. Louis, MO.

Rushed into the field by MG Halleck after Fremont's relief. Marched for anti-Guerrilla ops in north Missouri on Nov 21, 1861. As intended, they were armed with hand-made octagonal barrel Plains Rifles (produced/procured by St. Louis master gunmaker Horace Dimick, a competitor of the Hawkin Brothers).

Officially designated "Birge's Western Sharpshooters". In de facto direct U.S. Service

The regiment was initially composed of: 4 x Missouri Companies, 3 x Illinois Companies, 2 x Ohio Companies, 1 x Michigan Companies. Individual sharpshooters from 7 other states. (Later one Missouri company [Captain Welker's "Original A"] was reassigned to the 26th Missouri [ as "Company B (Independent Sharpshooters)] and an Ohio company added was added to the WSS)

Designated as a permanently assigned skirmishing regiment (fighting every day when on campaign).

Fought at Mt. Zion Church (Hallsville, MO), Ft Donelson & Shiloh as "Birge's WSS" (It was during this early period that the regiment earned one of its nicknames, "The Squirrel Tail Regiment", from the grey "sugarloaf" hat, decorated at the crown with three squirrel tails, which had been specified as their uniform headgear by Gen Fremont and Col Birge. Sadly, it appears that this outlandish and colorful hat did not survive as part of their uniform beyond July 1862. Soldier diaries note a mass issue of regulation hats at that time.)

At Ft Donelson, they were one of only three units commended by BG Smith for their part in the successful charge of Feb 15, 1862. Also recognized for suppressing Confederate artillery on the Federal left (particularly the respected "Porter's Battery") for three days.

Single-handedly held the extreme Federal right on the disastrous 1st day (Apr 6, 1862) of Shiloh. Fought Terry's Texas Rangers (8th TX) and Brewer's Alabama and Mississippi (Cavalry) Battalion.

April 14, 1862, Redesignated "Western Sharpshooters-14th Missouri Volunteers"

Fight in the Corinth Campaign, Iuka, 2nd Corinth, and various minor actions as WSS-14th MO Vols.

Made one of the great stands in U.S. military history on the second day (Oct 4, 1862) of the (Second) Battle of Corinth. Ironically, serving as a Missouri (Federal) regiment, they held back Sterling Price's (Confederate) Missouri Brigade for several hours.

Jan 24, 1863, Gov Yates of IL uses his powerful political influence to have the regiment transferred to Illinois state control. Regiment redesignated as "66th Illinois Volunteer Infantry (Western Sharpshooters)". The"WSS" designation was retained in unit name by special request of commander Col Patrick E. Burke to Gov Yates.

The regiment was is allowed to continue recruiting in Missouri, Michigan, Ohio and other states to maintain the unit's multi-state character.

In Dec 1863. 470 members reenlised as veterans. Unit designated as "66th Illinois Veteran Volunteer Infantry (Western Sharpshooters)"

Nov 63-April 64: 250 members purchase 16-shot Henry Repeaters. 2nd largest private purchase of the war.

Participate in Atlanta Campaign. 2nd Brigade, 2nd Div, Left Wing, XVI Army Corps, Army of the Tennessee: usually used as skirmishers and scouts.

However, due to firepower generated by Henry's, they were increasingly used as shock troops.

Participated in most major actions of the campaign.

One detachment serves as bodyguards for Gen Grenville Dodge.

Fifty of the "16-shooter men" are mounted on horseback to increase scouting mobility.

Most famous engagements of this period include:
Lead the break-through at Snake Creek Gap
Single-handedly captured the heights at Resaca, GA on May 9, 1864.
During the July 22, 1864 "Battle of Atlanta" fought three actions in one day, including recapturing (with the the troops of the 81st OH) "DeGress' Battery" of the 1st Illinois Lt Artillery.

Selected for March to the Sea. Participate as members of XV Army Corps.
Defeated over 900 Georgia milita (behind earthworks) at Eden Cross-Roads
Participated in the assault on Ft McAllister outside Savannah.

Participated in Carolinas Campaign
Last fight: Battle of Bentonville, NC
Participated in Grand Review, May 24, 1864
Mustered out: July 7, 1865
Listed in Adjutant General of Illinois official history simply as "66th Illinois Vet Vol Inf", effectively editing the unit's multi-state nature and special mission out of history.
During the war years, and after the war, most members simply referred to the regiment as the "Western Sharpshooters" and often signed their name with the honorific "W.S.S."
The Western Sharpshooters was one of the most extraordinary and most effective regiments of the war. It was the first federal sharpshooter regiment to go into action, and served the longest. The WSS fought in over 50 actions and 16 major battles. This hard-fighting corps of Western marksmen fought their way down to Atlanta, across the South to the sea, and north to Richmond. Their combat record is unsurpassed in the war.

They were also one of the most colorful. While they lost their "squirrel tail" hats after the Siege of Corinth, they remained unconventional in dress. As elite skirmishers there were usually on their own, far from higher command (and in dangerous conditions) so they apparently felt that they could dress as they pleased. In photographs I have yet to see more than two Western Sharpshooters wearing the same uniform: frock coats, shell jackets, sack coats, "state" jackets; cavalry jackets; what is apparently a Confederate pattern jacket tailored in Federal blue (!); kepis; forage caps; endless civilian hats, cavalry boots. Colonel Patrick Burke issued an order warning enlisted men against wearing officer's regalia, but that was likely the limit of his success in reigning in the individual spirit of these elite troops.