Uncle Sam is the personification of the federal government of the United States dating back to the 19th century.
He is usually depicted as an elderly gentleman in a star-studded top hat and a red bow tie.
Uncle Sam is often used colloquially for the IRS, which levies income tax on American citizens and corporations.
One of the most prominent depictions of Uncle Sam in popular culture is a poster of him pointing at the viewer with the words “I want YOU”, which was used for recruiting initiatives for the US Army.
Uncle Sam represents the US government, while Lady Liberty and Columbia represent the US as a nation.