*as delineated by its current international and state boundaries
1800 — Mount St. Helens (Washington) The eruption was seen by Native Americans. Oral tradition of NE Washington tribes noted many people starved to death the winter following the eruption.
1812 — Augustine Volcano (Alaska) Augustine has had six significant eruptions: 1812, 1883–1884, 1935, 1963–1964, 1976, and 1986. The 1883 eruption produced a tsunami.
1825 — Isanotski Peaks (Alaska) Also known as Isanotski Volcano, locally as “Ragged Jack,” is a multi-peaked mountain on Unimak Island, the easternmost Aleutian Island. Other eruptions occurred in the 1940s.
1912 — Novarupta (Alaska) Newly formed volcano in that year, located on the Alaska Peninsula on a slope of Trident Volcano in Katmai National Park and Preserve. Largest volcanic eruption of the 20th century; Novarupta released 30 times the volume of magma of the 1980 eruption of Mount St. Helens.
1915 — Lassen Peak (California) First volcano in the Cascades Volcanic Arc heading northwards, possibly the first volcanic eruption recorded using motion picture camera. Pyroclastic flows caused massive fires and evidence of the eruption still present (as of 2020) in form of charred trees and unusual tree growth patterns. It is now Lassen Volcanic National Park.
1931 — Mount Aniakchak (Alaska) Located in the Aleutian Range, the pre-existing mountain collapsed in a major eruption forming a six-mile diameter caldera.
1953 — Mount Spurr (Alaska) A stratovolcano in the Aleutian Arc of Alaska named after USGS geologist and explorer Josiah Edward Spurr (who led an expedition to the area in 1898). The mountain is known aboriginally by the Dena’ina Athabascan name K’idazq’eni, literally “that which is burning inside.”
1976 — Augustine Volcano (Alaska) [See 1812 reference]
1980 — Mount St. Helens (Washington) Most deadly and economically destructive volcanic eruption in US history. Ash from the eruption reached into Montana. Large forest fire resulted from one of the 17 pyroclastic flows. The sound of eruption could be heard 700 miles away; an entire flank of the mountain collapsed. Also notable was the extremely large lahar that flooded the banks of the Toutle River and destroyed bridges. [See 1800 reference]
Read more at “When the sky fell.”
1981 — North Pagan ([Commonwealth of] Northern Mariana Islands) Pagan is a volcanic island in the Marianas archipelago in the northwest Pacific Ocean The island has been largely uninhabited ever since most of the residents were evacuated due to volcanic eruptions in 1981.
1986 — Augustine Volcano (Alaska) [See 1812 reference]
1989–1990 — Mount Redoubt (Alaska) Second costliest volcanic eruption in United States history. Caused engine failure of all four engines on KLM Flight 867 after it flew through the ash cloud. After falling 14,000 the crew managed to restart engines and safely land in Anchorage.
1992 — Mount Spurr (Alaska) [See 1953 reference]
2008 — Mount Okmok (Alaska) Mount Okmok the highest point on the rim of Okmok Caldera on the northeastern part of Umnak Island in the eastern Aleutian Islands.
2008 — Kasatochi Volcano (Alaska) Also known as Kasatochi Island, it is an active stratovolcano and part of the Andreanof Islands subgroup of the Aleutian Islands.
Note: While Hawaii has several active volcanos and ones currently erupting, they are not considered large eruptions by VEI comparison and most of their damage is done by lava flows. Mauna Loa, the largest volcano on earth, has erupted 33 times since 1843.
Sources: Wikipedia and United States Geological Survey