About 900 students received their degrees at the Cross Insurance Arena in Portland.
It was an emotional day for many graduating students and their families -- and some students were already getting nostalgic for the state of Maine and the city of Portland.
"It's a small community where you feel like you know everyone. You can find everyone on the street the next day and say hi to them. It just feels like home," said USM graduate Jarvis Thanex.
When talking about their hard work, Mills joked in her speech that none of the students got there by pretending they were on a crew team -- a shot at the ongoing college admissions scandal.
Saturday's commencement was the school's 139th to date.