The following is a list of American Conflicts from 1800-1991 from OnWar.com.   Further links and explanations are found there.

Gabriel's Revolt in Virginia 1800
Tripolitan War 1801-05
US Occupation of West Florida 1810
Tecumseh's War 1811
War of 1812
Fort Mims Massacre 1813
Creek War 1813-14
Algerine War 1815
First Seminole War 1817-18
Vesy's Rebellion 1822
Arikara "War" 1823
Fredonian Rebellion 1826-7
Turner's Rebellion 1831
Black Hawk's War 1832
Texan Independence War 1835-36
Indian Stream "War" 1835
Murrel's Rebellion 1835
Second Seminole War 1835-43
Aroostook War 1838-39
Buckshot War 1838
Amistad Mutiny 1939
The Creole Mutiny 1841
Dorr's Rebellion in Rhode Island 1842
Mexican-American War 1846-48
Bear Flag Revolt in California 1846
Whitman Massacre 1847
Cayuse War 1848-55
Third Seminole War 1855-58
Rogue River Wars 1855-6
Wakarusa War 1855
Yakima War 1855-8
Pottawatomie Massacre 1856
Spirit Lake Massacre 1857
Mountain Meadows Massacre 1857
Utah War 1857-8
Brown's Raid on Harpers Ferry 1859
Apache and Navaho War 1860-5
American Civil War 1861-65
Sioux War 1862-64
Sand Creek Massacre 1864
Cheyenne & Arapaho War 1864-68
Saint Albans Raid 1864
Sioux War 1865-68
Fenian Raiders 1866-70
Fetterman Massacre 1866
Wagon Box Fight 1867
Blood River Massacre in  Montana 1870
Camp Grant Massacre 1871
Apache War 1871-73
Modoc War 1872-3
Kiowa War 1874
Red River Indian War 1874-75
Apache War 1876-83
Sioux War 1876-77
Nez Perce War 1877
Bannock War 1878
Cheyenne War 1878
Victorio's Apache Raiding 1879
Apache War 1885-6
Sioux War 1890-91  Samoan Civil War 1898-99
Spanish-American War 1898
Philippine-American War 1899-1902
Assassination of McKinley 1901
Moro Resistance: Philippines 1901-13
Panamanian Secession 1903
Black Patch War 1904-9
American Occupation of Cuba 1906-7
Haitian Revolt 1915
Poncho Villa's Raids 1916-17
Preparedness Day Bombing in America 1916
Cuban Revolt of 1917
Dominican Occupation Revolt 1917-21
World War I 1917-18
Russian Civil War 1918-20
Haitian Occupation Revolt 1918
Costa Rican Counterrevolution 1919
Costa Rican-Panamanian Border Clash 1921
Panama City Rent Riot 1925
"Bonus Marchers" Intervention 1932
Sakdal Uprising in the Philippines 1935
Panay Incident in China 1937
World War II 1939-45
Korean Occupation Rebellion 1946
Berlin Blockade 1948-9
Korean Guerrilla War 1948-9
Ysu Rebellion in US Occupied Korea 1948
Attack on Blair House 1950
Anglo-American Plot: Albania 1950-2
Korean War 1950-53
Nationalist Uprising in Puerto Rico 1950
Anglo-American Plot: Iran 1953
The U-2 Incident 1960
Bay of Pigs Invasion 1961
Berlin Wall Crisis 1961
Cuban Missile Crisis 1962
Pathet Lao Insurgency 1962-75
Panama: Anti-American Rioting 1964
Gulf of Tonkin Incident 1964
Dominican Civil War 1965
Black Panthers in America 1966-73
Pueblo Incident 1968
Trinidadian Rebellion 1970
Mayaguez Incident: Cambodia 1975
Panama Canal Negotiation Crisis 1975
Peace Village Incident 1976
Panama Canal Treaty Ratification 1977
Dominican Electoral Intervention 1978
Jonestown, Guyana 1978
US Ambassador: Afghanistan 1979
Iran Hostage Crisis 1979-81
Libyan Airspace Incident 1981
Shooting Down of KAL007: 1983
American Raid on Libya 1986
Stark Incident 1987
Strait of Hormuz Incident 1988
Libyan Fighters Incident 1989
US Invasion of Panama 1989
Collapse of the Berlin Wall 1989-90
Persian Gulf War 1990-91

See the soldiers at the image source.