1861

Four members of the Baltimore, Maryland, Police Board were arrested by Federal authorities because of their alleged pro-Confederate activities within the city.

1862

Skirmishes at Booneville and Holly Springs, Mississippi.

Skirmish at Cherry Grove, in Schuyler County, Missouri.

Skirmish near Fort Furnace, Powell’s Big Fort Valley, Virginia.

The US Government approves the building of a trans-continental railroad across the west, which will become the Union Pacific and the Central Pacific Railroad.

The US Government revises the Federal Income Tax Law with 3% on income between $600 and $10,000 and 5% on income above $10,000.

President Lincoln announced to Northern governors he was calling for 300,000 more men to “bring this unnecessary and injurious civil war to a speedy and satisfactory end.”.

Battle of Malvern Hill, Virginia, where Union artillery cuts down Confederate attackers on the last of the Seven Days' battles.

1863

In the North, discontent was mounting over the draft.

In the South, discontent was growing with the Davis administration in Richmond, between general officers in the field, and with economic hardships.

Skirmish at Christiansburg, Kentucky.

Skirmish at Cabin Creek, the Indian Territory.

Skirmish at Baltimore Cross Roads, Maryland.

During the day 45 in the siege at Vicksburg, Mississippi, a skirmish occurs at Edwards Station, Mississippi.

Skirmish at Carlisle, Pennsylvania.

Skirmishes near Bethpage Bridge on the Elk River, Tennessee, and another near Bobo’s Cross Roads, Tennessee.  Tullahoma, Tennessee is occupied by Maj. Gen. William S. Rosecrans, USA, Federal forces.

Federal operation between White House and South Anna River in Virginia.

The Battle of Gettysburg begins.  The largest military conflict in North American history begins this day when Union and Confederate forces collide at Gettysburg. The epic battle lasted three days and resulted in a retreat to Virginia by Robert E. Lee's Army of Northern Virginia.

Two months prior to Gettysburg, Lee had dealt a stunning defeat to the Army of the Potomac at Chancellorsville. He then made plans for a Northern invasion in order to relieve pressure on war-weary Virginia and to seize the initiative from the Yankees. His army, numbering about 80,000, began moving on June 3. The Army of the Potomac, commanded by Joseph Hooker and numbering just under 100,000, began moving shortly thereafter, staying between Lee and Washington, D.C. But on June 28, frustrated by the Lincoln administration's restrictions on his autonomy as commander, Hooker resigned and was replaced by George G. Meade.

Meade took command of the Army of the Potomac as Lee's army moved into Pennsylvania. On the morning of July 1, advance units of the forces came into contact with one another just outside of Gettysburg. The sound of battle attracted other units, and by noon the conflict was raging. During the first hours of battle, Union General John Reynolds was killed, and the Yankees found that they were outnumbered. The battle lines ran around the northwestern rim of Gettysburg. The Confederates applied pressure all along the Union front, and they slowly drove the Yankees through the town.

By evening, the Federal troops rallied on high ground on the southeastern edge of Gettysburg. As more troops arrived, Meade's army formed a three-mile long, fishhook-shaped line running from Culp's Hill on the right flank, along Cemetery Hill and Cemetery Ridge, to the base of Little Round Top. The Confederates held Gettysburg, and stretched along a six-mile arc around the Union position. For the next two days, Lee would batter each end of the Union position, and on July 3, he would launch Pickett's charge against the Union center.

1864

Multiple skirmishes at Allatoona, Howell’s Ferry, and Lost Mountain, Georgia.

Beginning of a month long Federal operation on the west coast of Florida.

Day one of a ten day Federal operation against Sioux Indians in the District of Minnesota.

Skirmish in the vicinity of Fayette, Missouri.

1865

New Hampshire becomes the 21st state to rarify the 13th amendment which will abolish slavery.

References:

The Civil War Day by Day, Philip Katcher
The Civil War Day By Day: An Almanac 1861-1865, by E. B. Long with Barbara Long
The Chronological Tracking of the American Civil War Per the Official Records of the War of Rebellion, by Ronald A Mosocco
http://www.history.com/this-day-in-history.do
http://www.on-this-day.com/cgi-bin/otd/uscivilwarotd/uscivilwarotd.pl