The last USA declared war was in WW2. Here are the undeclared wars where Americans have died since then:
1947–1949: Intervening in the Greek civil war
1947–1970: Meddling in Italy's elections and supporting anti-communism activities
1945-1949: Intervening in China’s civil war and establishing Taiwan
1948: Supporting anti-government forces in Costa Rica's civil war
1949–1953: Supporting anti-communism activities in Albania
1949: Staging a coup in Syria (it was CIA’s first coup)
1950–1953: Korean War
1952: Intervening in the Egyptian Revolution of 1952
1953: Orchestrated a coup in Iran and overthrew the democratically elected leader
1954: Invaded Guatemala and installed a puppet
1956–1957: Plotting a coup in Syria
1957–1959: Supporting a coup in Indonesia
1958: Creating a crisis in Lebanon
1960–1961: Supporting a coup in the Congo
1960: Meddling in Laos’ reforms
1961: Bay of Pigs invasion of Cuba
1961–1975: Supporting civil war and OPIUM TRADE in Laos (look up “Air America”)
1961–1964: Supporting anti-government activities in Brazil
1963: Supporting civil strife in Iraq
1963: Supporting riots in Ecuador
1963–1975: Vietnam War
1964: Intervening in Congo’s rebellion (and bombing)
1965–1966: Intervening in Dominica's civil war
1965–1967: Installing, arming and aiding fascist Indonesian military government’s massacre of communists (2-3 million killed)
1966: Engineering an insurgency in Ghana
1966–1969: Creating conflicts in the Demilitarized Zone (DMZ), which is a region on the Korean peninsula that demarcates North Korea from South Korea
1966–1967: Supporting an insurgency in Bolivia
1967: Intervening in the change of the Greek government
1967–1975: Intervening in Cambodia's civil war
1970: Meddling in Oman's domestic affairs
1970–1973: Aided a military coup in Chile (overthrew democratically elected and popular progressive leader, Salvador Allende)
1970–1973: Orchestrating a coup in Cambodia
1971: Supporting a coup in Bolivia
1972–1975: Assisting anti-government forces in Iraq
1976: Supporting a coup in Argentina
1976–1992: Intervening in Angola's domestic affairs
1977–1988: Supporting a coup in Pakistan
1979–1993: Supporting anti-government forces in Cambodia
1979–1989: Arming, funding, training the Mujahedin in Afghanistan. This led to Al Qaeda and the largest network of Islamic terrorist groups in the world.
1979–1989: Used Saddam Hussein to wage a proxy war against Iraq. Funded and armed Saddam for ten years.
1980–1989: Financed anti-government Solidarity trade union in Poland
1980–1992: Meddling in El Salvador's civil war
1981: Attacking Libya in Gulf of Sidra
1981–1982: Engineering regime change in Chad
1982–1984: Participating in a multilateral intervention in Lebanon
1982–1989: Supporting anti-government forces in Nicaragua (the U.S. armed fascists, death squads, drug lords etc.)
1983: Invading Grenada
1986: Invading Gulf of Sidra, Libya
1986: Bombing Libya
1988: Shooting down an Iranian airliner
1988: Sending troops to Honduras
1989: Attacking Libya in Tobruk
1989: Intervening in the Philippines' domestic affairs
1989–1990: Invading Panama
1990–1991: Persian Gulf War, Part 1
1991: Intervening in Haiti's elections
1991–2003: Leading the enforcement action to establish a no-fly zone in Iraq
1992–1995: Intervening in Somalia's civil war for the first time
1992–1995: Intervening in the Bosnian War
1994–1995: Sending troops to Haiti
1996: Supporting a coup in Iraq
1997: Sending troops to Albania
1997: Sending troops to Sierra Leone
1998–1999: Waging the Kosovo War
1998: Launching cruise missile attacks on Sudan and Afghanistan
1998–1999: Sending troops to Kenya and Tanzania
2001–present: War on Afghanistan
2002: Sending troops to Côte d'Ivoire
2003: Orchestrating color revolution in Georgia and installing a pro-US government
2003–present: Iraq War, Part 2
2004–now: Inciting wars between Pakistan and Afghanistan in their contiguous areas
2004: Orchestrating color revolution in Ukraine and installing a pro-US government
2006–2007: Supporting Fatah, a Palestinian political and military organization, in overthrowing the elected government of Hamas
2007–present: Intervening in Somalia's civil war for the second time
2009: Supporting a coup in Honduras
2011: Supporting anti-government forces in Libya
2011–present: Arming, funding, training jihadists, Al Qaeda, and “moderate rebels” in Syria. Occasionally bombing Syria. And occupying the oil-rich parts of Syria.
2011–2017: Carrying out military operations in Uganda
2014: Orchestrating a color revolution in Ukraine and overthrowing a democratically elected leader.
2014–present: Leading the intervention actions in Iraq
2015–now: Arming, directing Saudi Arabia's participation in Yemen's civil war
2017-2019: Attempting regime change in Venezuela
2012-2020: Funding, orchestrating riots in Hong Kong.
2019: Supporting a military coup in Bolivia
1990s-now: Funding Uyghur separatists and trying to break the Xinjiang province off China.
2022-? Now we are in Ukraine, fighting their war for them and Biden is giving billions of our tax payer money, so that the Ukrainian government pensioners retirement accounts are all fat and fluffy.....