The Essex Brigade, later 161st Brigade and 161st Infantry Brigade, was a volunteer infantry formation of the British Army in existence from 1888 until 1941, and again from 1947.
 It served at Gallipoli and in Palestine during World War I and returned to Egypt in the early part of World War II before transferring to the British Indian Army and redesignated 161st Indian Infantry Brigade.
 In peacetime and during the wars the brigade was an integral part of the 54th (East Anglian) Infantry Division and contained mostly battalions of the Essex Regiment.
The American Civil War (commonly known as the "Civil War" in the United States) was fought in the United States from 1861 to 1865.
 The result of a long-standing controversy over slavery, war broke out in April 1861, when Confederates attacked Fort Sumter in South Carolina, shortly after Abraham Lincoln was inaugurated.
 The nationalists of the Union proclaimed loyalty to the U.S. Constitution.
 They faced secessionists of the Confederate States of America, who advocated for states’ rights to perpetual slavery and its expansion in the Americas.
The 161st New York Volunteer Infantry Regiment was an infantry regiment of the Union Army during the American Civil War.
The 124th New York Volunteer Infantry Regiment, commonly known as the Orange Blossoms, was a volunteer regiment from Orange County, New York, during the American Civil War.
 Formed in Goshen during the summer of 1862, The unit was officially mustered into United States Service on September 5, 1862, by Col. Augustus van Horne Ellis, the regiment was made up of volunteers from the surrounding towns and a core of veterans from the 71st New York State Militia.
The 161st Ohio Volunteer Infantry (or 161st OVI) was an infantry regiment in the Union Army during the American Civil War.
The 91st New York Volunteer Infantry Regiment was a state infantry regiment formed during the American Civil War from counties around Albany, New York.
The 31st New York Volunteer Infantry Regiment, "Baxter's Light Guard" or the "Montezuma Regiment", was an infantry regiment that served in the Union Army during the American Civil War.
The 61st New York Volunteer Infantry Regiment, also known as the "Astor Regiment", was an infantry regiment of the Union Army during the American Civil War.
The 41st New York Volunteer Infantry Regiment was an infantry regiment that served in the American Civil War.
 They were nicknamed Dekalbs Zouaves for their gaudy French/American zouave style.
 Consisting of a dark blue and green zouave jacket with red trimmings, dark blue pantaloons with red braiding, a sky blue sash, a dark blue zouave vest with red trimming, a red tassled fez with a thin yellow band around it, and white gaiters.
 The 41st New York Volunteer Infantry, was first formed to rebel against the Union when talks of secession were under talk.
 The regiment succeeded becoming known for their connections with the confederacy although, they were stopped early in the war and turned over to fight for the Union.
 They were also the only "zouave" regiment in the 11th Corps.
 The regiment also wore a uniform that was based on the Jaeger uniform of Germany.
 It consisted of a dark green frock coat with red trimming and cuff flaps, dark green pants with a red stripe down the leg, a dark green kepi with a red band, and black shoes.
The 121st New York Volunteer Infantry Regiment, commonly known as the "Onesers" or "Upton's Regulars", was a volunteer regiment recruited during the American Civil War from Otsego County and Herkimer County, New York.
 The Hon. Richard Franchot was appointed colonel of the regiment and authorized to establish his headquarters at Richfield Springs, Otsego County.
 He proceeded without delay to organize the regiment, and on August 23, 1862, the regiment was mustered into the service of the Union Army.
 The command at that time consisted of 39 officers and 946 enlisted men.
 The 121st Regiment proceeded to Washington, arriving there on the morning of September 3, and was assigned provisionally to a brigade under Colonel Gibson with headquarters at Fort Lincoln.

Question: The 161st New York Volunteer Infantry Regiment participated in a war that began shortly after which presidents inaguration?
Answer: Abraham Lincoln