On April 12, 1861, Confederate forces fired on Union troops at Fort Sumter, forcing them to surrender, and began the war.

On April 15, Lincoln called on all the states to send detachments totaling 75, 000 troops to recapture forts, protect Washington, and " preserve the Union ", which, in his view, still existed intact despite the actions of the seceding states.

On April 19, secessionist mobs in Baltimore that controlled the rail links attacked Union troops traveling to the capital.

Union enlistments from Maryland, Kentucky, and Missouri increased by over 40, 000 troops.

" With Grant in command, Lincoln felt the Union Army could relentlessly pursue a series of coordinated offensives in multiple theaters, and have a top commander who agreed on the use of black troops.

Gen. Felix Zollicoffer with 4, 000 men to occupy Cumberland Gap in Kentucky in order to block Union troops from coming into eastern Tennessee.

Zollicoffer decided it was impossible to obey orders to return to the other side of the river because of scarcity of transport and proximity of Union troops.

As the Confederate forces overran the Union camps, Johnston seemed to be everywhere, personally leading and rallying troops up and down the line on his horse.

* 1862 – American Civil War: The Battle of Shiloh begins – in Tennessee, forces under Union General Ulysses S. Grant meet Confederate troops led by General Albert Sidney Johnston.

* 1864 – American Civil War: Battle of Gainesville – Confederate forces defeat Union troops near Gainesville, Florida.

By that September Johnson declared he was in favor of emancipation, describing slavery as a " cancer on our society ", and also succeeded in enlisting 20, 000 black troops for the Union.

* 1863 – American Civil War: Grierson's Raid begins – troops under Union Army Colonel Benjamin Grierson attack central Mississippi.

* 1865 – American Civil War: The Siege of Petersburg is broken – Union troops capture the trenches around Petersburg, Virginia, forcing Confederate General Robert E. Lee to retreat.

* 1988 – In a United Nations ceremony in Geneva, Switzerland, the Soviet Union signs an agreement pledging to withdraw its troops from Afghanistan.

Carnegie helped open the rail lines into Washington D. C. that the rebels had cut ; he rode the locomotive pulling the first brigade of Union troops to reach Washington D. C.

* 1862 – American Civil War: Battle of Baton Rouge – along the Mississippi River near Baton Rouge, Louisiana, Confederate troops attempt to take the city, but are driven back by fire from Union gunboats.

* 1945 – Cold War: Yugoslav leader Josip " Tito " Broz signs an agreement with the Soviet Union to allow " temporary entry of Soviet troops into Yugoslav territory ".

* 1861 – American Civil War: Battle of Wilson's Creek – the war enters Missouri when a band of raw Confederate troops defeat Union forces in the southwestern part of the state.

* 1865 – American Civil War: A day after his surrender to Union forces, Confederate General Robert E. Lee addresses his troops for the last time.

Even though Bulgaria did not send any troops to support the German invasion of the Soviet Union, the Navy was involved in a number of skirmishes with the Soviet Black Sea Fleet, which attacked Bulgarian shipping.

While the CIA and MI6 and the People's Liberation Army of China financed the operation along with the Pakistan government against the Soviet Union Eventually the Soviet Union began looking for a withdrawal route and in 1988 Geneva Accords were signed between Communist-Afghanistan and the Islamic Republic of Pakistan ; under the terms Soviet troops were to withdraw.

Lumumba demanded that Belgium remove its troops immediately, threatening to seek help from the Soviet Union if they did not leave within two days.

In September 1861, Atchison led 3, 500 State Guard recruits across the Missouri River to reinforce Price, and defeated Union troops that tried to block his force in the Battle of Liberty.

* 1864 – American Civil War: Sherman's March to the Sea – Major General William Tecumseh Sherman's Union Army troops reach the outer Confederate defenses of Savannah, Georgia.

* 1941 – Tallinn, the Capital of Estonia is occupied by Nazi Germany following an occupation by the Soviet Union.

In 1940 Estonia was occupied by the Soviet Union.

The Tief government, though, lasted for only 5 days, as Estonia was again occupied by the Soviet Union.

When Estonia was invaded and occupied by the Soviet Union in World War II, the status of the Estonian language changed to the first of two official languages ( Russian being the other one ).

* 1939 – 1945: In World War II many countries are occupied by Germany and the Soviet Union, where Esperanto organisations often were prohibited or Esperanto activities were limited in other ways.

* 1940 – The Soviet Union begins mass deportations of Polish citizens from occupied eastern Poland to Siberia.

In 1940 the Soviet Union occupied Estonia, Latvia, Lithuania, Bessarabia ( now the Republic of Moldova ) and Bukovina.

The city of Atlanta was abandoned by Hood and then occupied by Union troops for the rest of the war.

The German Democratic Republic ( GDR ; German: Deutsche Demokratische Republik or DDR ), informally known as East Germany ( German: Ostdeutschland ), was a socialist state established by the Soviet Union in 1949 out of the Soviet zone of occupied Germany, including East Berlin of the Allied-occupied capital city.

After World War II, the Soviet Union installed socialist regimes modelled on those it had installed in 1919 – 20 in the old Tsarist empire in areas its forces occupied in Eastern Europe.

Stalin insisted that, after the war, the Soviet Union should incorporate the portions of Poland it occupied pursuant to the Molotov-Ribbentrop Pact with Germany, which Churchill opposed.

* 1944 – World War II: the Soviet Union invades East Karelia and the previously Finnish part of Karelia, occupied by Finland since 1941.

After declaring independence from the Soviet political structure completely dominated by Moscow and the Communist Party of the Soviet Union ( CPSU ) until 1991, Kazakhstan retained the basic governmental structure and, in fact, most of the same leadership that had occupied the top levels of power in 1990.

In that year, it was occupied by the Soviet Union and annexed according to the Potsdam Agreement.

Although the First Battle of Independence in August 1862 resulted in a Confederate victory, the Southerners were unable to follow up their win in any significant fashion, as the City of Kansas was occupied by Union troops and proved too heavily fortified for them to assault.

Latvia's independent status was interrupted at the outset of World War II when in 1940 the country was forcibly incorporated into the Soviet Union, invaded and occupied by Nazi Germany in 1941, then retaken by the Soviets in 1944 after Germany surrendered.

It remained independent until the outset of World War II, when it was occupied by the Soviet Union under the terms of the Molotov – Ribbentrop Pact.

Between 28 June and 4 July, the Soviet Union occupied and annexed Bessarabia, Northern Bukovina and the Hertza region of Romania.

The Korean peninsula was divided into two occupied zones in 1945, with the northern half of the peninsula occupied by the Soviet Union and the southern half by the United States.

Tactically, the Germans won resounding victories and occupied some of the most important economic areas of the Soviet Union, mainly in Ukraine.

Post-independence, it has fought three wars against India, several border skirmishes with Afghanistan and against the Soviet Union which occupied Afghanistan in 1979, and an extended border skirmish with India in 1999 ( Kargil War ) and is currently conducting anti-terrorist operations along the border areas of Afghanistan.

The Antonescu regime played a major role in the Holocaust, following to a lesser extent the Nazi policy of oppression and massacre of the Jews, and Romas, primarily in the Eastern territories Romania recovered or occupied from the Soviet Union ( Transnistria ) and in Moldavia.

After World War II started, Estonia was occupied by the Soviet Union ( USSR ) in 1940, and later occupied by Nazi Germany from 1941 to 1944.