Final answer:
The Second Seminole War was considered the longest foreign war waged by the United States up until the war in Vietnam.
Step-by-step explanation:
The war considered the longest foreign war waged by the United States up until the war in Vietnam was The Second Seminole War.
It lasted from 1835 to 1842, making it a 7-year conflict. It was fought between the United States and the Seminole tribe in Florida.
The war was driven by conflicts over land and the expulsion of the Seminole people. The U.S. eventually managed to remove most of the Seminoles from Florida, but it was a costly and challenging campaign.
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