Lieutenant Governor of Kansas: Thomas Andrew Osborn (Republican)
Lieutenant Governor of Kentucky: Richard Taylor Jacob (Democratic) (until month and day unknown), vacant (starting month and day unknown)
Lieutenant Governor of Louisiana: Henry M. Hyams (Democratic) (until month and day unknown), Benjamin W. Pearce (Republican) (starting month and day unknown)
Lieutenant Governor of Massachusetts: Joel Hayden (Republican)
January – Long Walk of the Navajo: Bands of Navajo led by the U.S. Army are relocated from their traditional lands in eastern Arizona Territory and western New Mexico Territory to Fort Sumner in the Pecos River valley. At least 200 died along the 300-mile (480 km) trek that took over 18 days to travel on foot.
January 13 – Songwriter Stephen Foster ("Oh! Susanna", "Old Folks at Home") dies aged 37 in New York City leaving a scrap of paper reading "Dear friends and gentle hearts". His parlor song "Beautiful Dreamer" is published in March.
February 9 – American Civil War: Libby Prison escape – 109 Union soldiers escape from the Confederate prison in Richmond, Virginia, 59 making it back to their home territory.
February 17 – American Civil War: The tiny Confederate submarineHunleytorpedoes the USS Housatonic, becoming the first submarine to sink an enemy ship (the sub and her crew of 8 are also lost).
February 20 – American Civil War: The Union suffers one of its costliest defeats at the Battle of Olustee near Lake City, Florida.
February 25 – American Civil War: The first Northern prisoners arrive at the Confederate prison at Andersonville, Georgia (the 500 prisoners had left Richmond, Virginia, 7 days before).
March[]
March 9: Ulysses S. Grant commands all Union armies
March 9 – American Civil War: President Abraham Lincoln appoints Ulysses S. Grant commander in chief of all Union armies.
March 10 – American Civil War: The Red River Campaign begins as Union troops reach Alexandria, Louisiana.
April[]
April 22 – The U.S. Congress passes the Coinage Act of 1864 which mandates that the inscription "In God We Trust" be placed on all coins minted as United States currency.
May[]
May – Man and Nature: or, Physical geography as modified by human action by George Perkins Marsh is published. One of the first works to document the effects of human action on the environment and it helped to launch the modern conservation movement.
May 5 – American Civil War: The Battle of the Wilderness begins in Spotsylvania County, Virginia.
May 7 – American Civil War: The Army of the Potomac, under General Ulysses S. Grant, breaks off from the Battle of the Wilderness and moves southwards.
May 8–21 – American Civil War – Battle of Spotsylvania Court House: Some 4,000 die in an inconclusive engagement.
May 11 – American Civil War – Battle of Yellow Tavern: Confederate General J. E. B. Stuart is mortally wounded at Yellow Tavern, Virginia.
May 12 – American Civil War – Battle of Spotsylvania Court House: The "Bloody Angle" – thousands of Union and Confederate soldiers die.
May 13 – American Civil War – Battle of Resaca: The battle begins with Union General Sherman fighting toward Atlanta.
May 18 – Civil War gold hoax: The New York World and the New York Journal of Commerce publish a fake proclamation that President Abraham Lincoln has issued a draft of 400,000 more soldiers.
May 20 – American Civil War – Battle of Ware Bottom Church: In the Virginia Bermuda Hundred Campaign, 10,000 troops fight in this Confederate victory.
May 26 – Montana Territory is organized out of parts of Washington Territory and Dakota Territory, and is signed into law by President Abraham Lincoln.
June[]
June 5 – American Civil War – Battle of Piedmont: Union forces under General David Hunter defeat a Confederate army at Piedmont, Augusta County, Virginia, taking nearly 1,000 prisoners.
June 9 – American Civil War – The Siege of Petersburg begins. Union forces under General Grant and troops led by Confederate General Robert E. Lee battle for the last time.
American Civil War – Battle of Brice's Crossroads: Confederate troops under Nathan Bedford Forrest defeat a much larger Union force led by General Samuel D. Sturgis in Mississippi.
June 12 – American Civil War – Battle of Cold Harbor: General Ulysses S. Grant pulls his troops from their positions at Cold Harbor, Virginia and moves south.
June 15 – Arlington National Cemetery is established when 200 acres (0.8 km²) of the grounds of Robert E. Lee's home Arlington House are officially set-aside as a military cemetery by U.S. Secretary of War Edwin M. Stanton.
June 27 – American Civil War: Battle of Kennesaw Mountain near Kennesaw, Georgia.
June 30 – President Abraham Lincoln signs the Yosemite Grant Act, precursor to Yosemite National Park.
July[]
July – President Abraham Lincoln signs a law that abolishes the commutation fee that could be paid to in lieu of conscription.
July 20 – American Civil War – Battle of Peachtree Creek: Near Atlanta, Georgia, Confederate forces led by General John Bell Hood unsuccessfully attack Union troops under General William T. Sherman.
July 22 – American Civil War – Battle of Atlanta: Outside of Atlanta, Georgia, Confederate General Hood leads an unsuccessful attack on Union troops under General Sherman on Bald Hill.
July 24 – American Civil War – Battle of Kernstown: Confederate General Jubal Early defeats Union troops led by General George Crook in an effort to keep the Yankees out of the Shenandoah Valley.
July 28 – American Civil War – Battle of Ezra Church: Confederate troops led by General Hood make a third unsuccessful attempt to drive Union forces under General Sherman from Atlanta, Georgia.
July 30 – American Civil War – Battle of the Crater: Union forces attempt to break Confederate lines by exploding a large bomb under their trenches.
August[]
August 1 – The Elgin Watch Company is founded in Elgin, Illinois.
August 5 – American Civil War – Battle of Mobile Bay: At Mobile Bay near Mobile, Alabama, Admiral David Farragut leads a Union flotilla through Confederate defenses and seals one of the last major Southern ports.
August 18 – American Civil War – Battle of Globe Tavern: Forces under Union GeneralUlysses S. Grant try to cut a vital Confederate supply-line into Petersburg, Virginia, by attacking the Wilmington and Weldon Railroad, forcing the Confederates to use wagons.
August 31 – American Civil War: Union forces led by GeneralWilliam T. Sherman launch an assault on Atlanta, Georgia.
September[]
September 1 – American Civil War: Confederate General Hood evacuates Atlanta after a 4-month siege mounted by Union General Sherman.
September 2 – American Civil War: Union forces under General Sherman enter Atlanta a day after the Confederate defenders fled the city.
September 8 – American Civil War: Atlanta, Georgia is evacuated on orders of Union General William Tecumseh Sherman.
October[]
October 2 – American Civil War – Battle of Saltville: Union forces attack Saltville, Virginia but are defeated by Confederate troops.
October 15 – American Civil War – Battle of Glasgow, Missouri: Confederate forces take the town.
October 19 – American Civil War – Battle of Cedar Creek: Union forces under Philip Sheridan defeat a surprise Confederate attack although incurring nearly twice as many casualties, ending the Shenandoah Valley Campaigns of 1864.
October 25 – American Civil War – Battle of Mine Creek: the second largest cavalry engagement of the war, two divisions of Major GeneralSterling Price's Army of Missouri are routed by two Federal brigades under the command of ColonelsFrederick Benteen and John Finis Philips.
October 28 – American Civil War
Second Battle of Fair Oaks: Union forces under General Ulysses S. Grant withdraw from Fair Oaks, Virginia, after failing to breach the Confederate defenses around Richmond, Virginia.
October 30 – Helena, Montana is founded after four prospectors (the so-called Four Georgians) discover gold at Last Chance Gulch; it is their last and agreed final attempt at weeks of trying to find gold in the northern Rockies.
October 31 – Nevada is admitted as the 36th U.S. state (seeHistory of Nevada).
November 4 – American Civil War – Battle of Johnsonville: At Johnsonville, Tennessee, troops under the command of Confederate General Nathan Bedford Forrest bombard a Union supply base with artillery and destroy millions of dollars in material.
November 7 – The capital of Idaho Territory is moved from Lewiston to Boise; North Idaho declares the move illegal and proposes secession.
November 8 – U.S. presidential election, 1864: Abraham Lincoln is reelected in an overwhelming victory over George B. McClellan.
November 15 – American Civil War – Sherman's March to the Sea begins: Union General Sherman burns Atlanta and starts to move south, causing extensive devastation to crops and mills and living off the land.
November 22 – American Civil War – Sherman's March to the Sea: Confederate General John Bell Hood invades Tennessee in an unsuccessful attempt to draw Union General Sherman from Georgia.
November 25 – American Civil War: A group of Confederate operatives calling themselves the Confederate Army of Manhattan starts fires in more than 20 locations in an unsuccessful attempt to burn down New York City.
November 29 – Indian Wars – Sand Creek Massacre: Colorado volunteers led by Colonel John Chivington massacre at least 400[citation needed]Cheyenne and Arapahoe noncombatants at Sand Creek, Colorado (where they had been given permission to camp).
November 30 – American Civil War – Second Battle of Franklin: The Army of Tennessee led by General Hood mounts a dramatically unsuccessful frontal assault on Union positions around Franklin, Tennessee (Hood loses 6 generals and almost a third of his troops).
December[]
December 4 – American Civil War – Sherman's March to the Sea: At Waynesboro, Georgia, forces under Union General Judson Kilpatrick prevent troops led by Confederate General Joseph Wheeler from interfering with Union General Sherman's campaign of destroying a wide swath of the South on his march to Savannah, Georgia (Union forces suffer more than 3 times the casualties as the Confederates, however).
December 15–16 – American Civil War – Battle of Nashville: Union forces decisively defeat the Confederate Army of Tennessee.
December 21 – American Civil War – Sherman's March to the Sea: The campaign ends as Major General captures the port of Savannah, Georgia.
Undated[]
Asa Mercer travels from Seattle to the U.S. East Coast and recruits 11 Mercer Girls, potential wives for men on the West Coast.