Paul Allard Hodgkins, is the first man from Florida to be sent to prison after the riots at the US Capitol on January 6.
The 38-year-old man pleaded guilty to entering the Capitol to disrupt Congress. He was sentenced to an eight month jail term.
The prosecution called for an 18-month sentence after arguing that Hodgkins contributed to the collective threat to democracy.
This is the first of hundreds of riot cases at the Capitol. The FBI has so far arrested 535 people.
In Court, Hodgkins said the decision to take part in the protests was foolish. He stated that he regretted the damage done and that he had hurt his beloved country.
Footage shows the man in the Senate hall wearing a shirt supporting Donald Trump, with a Trump flag on his shoulder.
The Prosecution said Hodgkins was not violent and did not cause any harm.
In the past few days, a 49-year-old woman from Indiana, Anna Morgan-Lloyd, was given a three-year probation in connection with the Capitol riots.