It's the end of a (fashion) era!

President Barack Obama's final State of the Union address on Tuesday was a historic night for the Commander-in-Chief, but it also served as the last opportunity for Michelle Obama to show off her flawless first lady style -- and she pulled if off in a big way!

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Michelle, who has managed to cultivate her own unique brand of modern-yet-timeless elegance during her years as the first lady, shined bright like a ray of sunlight in a sleek, form-fitting, gown that showed off her iconic arms and accentuated her beaming smile.

Michelle, 51, looked marvelous in the marigold sleeveless banded-bodice midi dress by Narciso Rodriguez, and the gleaming gown was the perfect way to celebrate her illustrious time in the White House.

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As New York Times fashion critic Vanessa Friedman pointed out on Twitter, Michelle also rocked a striking Narciso Rodriguez gown in 2008, for her husband's historic election night victory, so there's a nice "symmetry" to her final State of the Union fashion choice.

A number of celebrities and fashion commenters also weighed in on Michelle's bold gown, heaping praise on the first lady for the "'60s-era glamour" her dress evoked.

WATCH: Michelle Obama Channels 'The Good Wife' With State of the Union Outfit

At the address, Michelle sat next to an empty seat, which was left unoccupied as a tribute to "the victims of gun violence who no longer have a voice," according to a statement released by the White House on Sunday.

Michelle is known for her bold State of the Union styles. In January 2015, she wore a striking grey Michael Kors suit with a zip-up top that was identical to an outfit worn by Julianna Margulies' character, Alicia Florrick, on The Good Wife. Check out the video below for a look at Michelle's Good Wife style.

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Michelle Obama: First Lady of Fashion