Inspired by sibling rivalry, Lachey taps his inner performer to get into a creative arts high school. He says to PEOPLE: "The only reason [brother Drew and I] even went to the same school was because my whole family was bragging and talking about how proud they were of Drew for getting in. Blah, blah, blah. I got sick of hearing about it, so I went down and auditioned too. I had no intention of going. I just wanted to prove I could get in."
Joining fellow Ohioan Jeff Timmons, Lachey, who has been studying sports medicine at Ohio's Miami University, decides to leave college for L.A. to form the band that eventually becomes 98 Degrees. High school pal Justin Jeffre and Lachey's younger brother Drew complete the quartet.
98 Degrees bags a Top 20 hit with "Invisible Man" off their self-titled debut album. "It's all very surreal, just a wild thing for us," Lachey tells The Cincinnati Enquirer. "I mean, I never in a million years thought that girls would look at us like that. But it's all very flattering." By the end of 1998, boy band mania is in full swing! Their album 98 Degrees and Rising spawns the Top 10 hit "Because of You."
Lachey meets 18-year-old singer Jessica Simpson at the Hollywood Christmas Parade. "After we met," Lachey says, "I found myself looking through the crowds for her all night." They hook up again at a Teen People party in Florida. Within weeks Lachey is telling fellow band members, "I'm going to marry that girl." Back in L.A., the pair begin dating.
Lachey sings the duet "Where You Are" with Simpson and follows it up with his 98 Degrees release called Revelation. That album, which peaked at No. 2 on Billboard's album charts, goes double-platinum and turns out to be the last the band records before taking a hiatus.
The golden couple breaks up. "Nick was patiently waiting for me to grow up a little," Simpson later tells PEOPLE. Lachey and Simpson reconcile after Sept. 11. "I knew that I never, ever wanted to be away from Nick for the rest of my life," Simpson says, adding later, he is "a man of character and a man of honor." On Feb. 10 2002, Lachey, 28, pops the question to Simpson, 21, with a pear-shaped diamond engagement ring, while vacationing on a yacht off the Hawaiian coast.
Lachey, 29, marries Simpson, 22, at a stone chapel in Austin, Texas, before about 350 guests. A teary-eyed Lachey serenades his bride with a song he wrote, "My Everything."
During appearances on MTV's Crib Crashers and Punk'd, Simpson and Lachey's chemistry shines, and they land their own reality show on the network: Newlyweds: Nick & Jessica. Their "Odd Couple" dynamics resonate with audiences. "Our roles are reversed: [Jessica] never puts on a new roll of toilet paper, she never makes the bed, she never picks up her clothes off the floor or puts away her shoes," Lachey says to PEOPLE. "I'm the woman in our relationship." Adds executive producer Rod Aissa: "The twist to this show is that while Jessica and Nick are stars, they're also real people who have to experience the dynamics of a real relationship."
Though 98 Degrees hasn't disbanded, Lachey makes his solo debut with SoulO. The romantic single "This I Swear" is featured as the Newlyweds theme song. But, despite the show's popularity, Lachey's album fails to crack 500,000 copies in sales.
With classic moments such as Simpson asking Lachey if a can of Chicken of the Sea tuna is chicken or fish, Newlyweds becomes America's guilty pleasure. As for the appeal, Lachey says on Larry King Live, "I think people can identify with the things that we go through, you know, as a newlywed couple and the fights and struggles."
BIOGRAPHY (top to bottom): Classmates Yearbook Archives; 20th Century FOX/Everett; Azzara Steve/Corbis Sygma; Tammie Arroyo; Joe Buissink/WireImage; NEAL PRESTON