Hussein, known for his anti-corruption policies and nationalism advocacy, led Somalia from 1964 to 1967 and was its United Nations ambassador from 1974 to 1979. He spent months in prison for demonstrating for Somali independence in 1950 and four years behind bars after a military coup overthrew the government in 1969.
"He was an icon for the community," activist Abdi Bihi told the (Minneapolis) Star Tribune.
"He never used one penny of public money. It's impossible in that part of the world."
Another activist, Omar Jamal, said Hussein, who died Friday, "transcended the conception of clan affiliation."
"In the eyes of Somalis, wherever they are, he is like George Washington," Jamal said.
"He died sad, having witnessed a country he once led disintegrating."
Hussein fled to the United States after a Socialist regime wrested control of Somalia, living in New York before moving to Minneapolis about 15 years ago.
Flags have been lowered in his home region of Puntland, the Star Tribune said.
He is survived by two daughters and a son.