The House wished Iranians and Iranian Americans a "prosperous new year" in a resolution ahead of Nowruz, a 3,000-year-old annual holiday that falls on Sunday with the start of spring.
"The United States is a melting pot of ethnicities and religion and Nowruz contributes to the richness of American culture and is consistent with our founding principles of peace and prosperity for all," it said.
It praised the Persian empire's founder Cyrus the Great, saying his sixth-century BC abolition of slavery and respect for religious freedom constituted "one of the earliest charters on human rights."
The resolution's sponsor, Democratic Representative Mike Honda, saluted accomplishments by the million-strong Iranian American community including in his district of California's Silicon Valley.
"This ancient holiday has survived centuries of religious differences and political rivalries, and is celebrated by a diverse group of people from different religious and ethnic backgrounds," Honda said.
A total of 384 members of Congress voted for the resolution and two voted against — Representatives Jeff Miller and Bill Posey, both conservative Republicans from Florida.
Another 44 lawmakers did not vote on the resolution, which was approved in the evening.
It marked the second time that the House has wished a Happy Nowruz after a first-of-a-kind resolution last year.
Last year, President Barack Obama also used Nowruz to make an unprecedented direct appeal to Iranians, extending a hand to turn the page on three decades of hostility since the Islamic revolution ousted the pro-Western shah.
The Obama administration has since voiced frustration at what they see as President Mahmoud Ahmadinejad's failure to reciprocate and has criticized the clerical regime for its contested nuclear program and human rights record.
