(FORTUNE Magazine) – While you were sleeping, they were up working--sorting packages, selling saws, creating software, mapping galaxies--unless, that is, you were up working too. Deep night, the once lonely landscape of gravediggers and lighthouse keepers, has been steadily colonized. Edgar Allan Poe's "midnight dreary" has become, for three million overnight workers in 21st-century America, early on in their day. "When I get to work, I tell everybody 'Good morning,'" says Walt Czarnik, night manager at a 24-hour Home Depot in Orlando. Come the witching hour in Atlanta, Denise Dillon, CNN Headline News overnight anchor, is just beginning her round of updates on the world. While traditional nighttime jobs endure--bar pilots still navigate ships through Charleston Harbor darkness, cops pace forlorn subways in New York City--the 24-hour economy has given rise to new forms of nocturnal toil. LaToya Odom, a FedEx package handler in Memphis, and David Scott, a Microsoft network technician in Redmond, Wash., have more in common than all-night hours. A generation ago neither FedEx's teeming Memphis hub nor Microsoft's pulsing Seattle campus was even on the map. At the Apache Point Observatory in New Mexico's Sacramento Mountains, Stephanie Snedden may work in the second-oldest nighttime profession, astronomy, but the universe-mapping tools she uses are contemporary: digital imaging, spectroscopy, and, for whisking hard data to far-off physicists, FedEx shipping. For Odom, hustling tons of packages by night enables her to be with her two kids by day. Ambition drives others. Dot-com partner Allison Paine, often at her Portland, Me., computer screen until dawn, says that night work flows from the demands of too short a day. "The Internet," she says, "has created a generation that works long hours." In 1942, Edward Hopper painted the melancholy masterpiece "Nighthawks," which showed a couple of men in fedoras and one red-headed woman leaning silently over a diner counter in New York's Greenwich Village. "I was painting the loneliness of a large city," Hopper said. The nighthawks in 2001 are proliferating, but rather than staring into space they are more likely to be surfing the Web. The clock on their screens, like yesteryear's clock on the wall, still tells the time--but the time, these nights, has a new story to tell.

The Dot-com Partner Allison Paine, StaffSheets, Portland, Me.

With Portland's 3 A.M. harbor lights visible through her window and a Web application on her screen, Allison Paine works in solitude, connected to the New York office of StaffSheets, a dot-com she helped found that links staffing companies, their corporate clients, and employees via the Internet. "The night is an extension of my day, my own second shift," says Paine, whose sunlit hours are spent in meetings and conference calls--and in traveling frequently to StaffSheets headquarters in Manhattan's Silicon Alley. Night offers space to develop software: "At night, time seems to open up full throttle, and you can ride it for all it's worth." An intensely focused 43-year-old, Paine relocated a few years ago from Brooklyn to Portland with her husband, a maritime historian, and their two young daughters, in an effort to balance career and motherhood. "Being a parent makes you realize how little sleep you can get by on," she says. Now the Down East darkness provides critical time to stay ahead. "The Internet has created the real notion of a race," she explains, "not necessarily to be best, but to be first." For Paine's own race--her day begins when she helps her daughters get ready for school at 6:45 A.M. and sometimes does not end until 4 A.M. when she turns off the computer--exhaustion is a hazard. "We all have our limits. To live the night as an extension of the day is only possible if you're jazzed by what you do. Sometimes you butt your head against a problem in the code, and it wears you out before you solve whatever mystery you've created for yourself. Then you're just beat tired. But if you unravel the thread, it's a good, rewarding night."

The Package Handler LaToya Odom, FedEx, Memphis

Between 10 and 11 P.M., 8,000 workers stream into the sprawling FedEx hub by the Memphis airport. LaToya Odom, 20, is among them--a strong-armed, gentle-voiced mother of two who earns her family's daily bread by nightly hauling her portion of more than one million packages. She joins the 17 members of Team 57 as they loosen up with leg stretches and head rolls. Then, receiving their first order, they pop in ear plugs and head to "wide-body row," where dozens of FedEx planes sit with holds open. Team 57's task: to offload an MD-11 just landed from Anchorage. In her second year on the job, Odom, recently named team leader, not only helps push crates but also hurries her fellow workers along--24 minutes, she says, is the goal for offloading 26 crates, each weighing up to 6,000 pounds. After the crates are driven to the sorting center, where the letters and boxes are mixed into a sea of others, computer-scanned, and sorted by destination, they are repacked onto outbound flights. Having never been a night person before starting with FedEx--"When the sun went down, I did too," she recalls--she finds that the schedule that initially brought confusion to her life now provides order, enabling her to pursue her ambition of becoming a nurse. (She goes to college during the day.) The hours also help her be a single working mother. "My grandmother, who kept me at night when I was little and my mother was working at the post office, is with my babies now when I'm working. They're asleep when I take them to her, and I've got them back home when they wake up. They think, 'Mommy's been here.'"

The Technician David Scott, Microsoft, Redmond, Wash.

In the monitor glow of a windowless hub at Microsoft's Redmond campus, David Scott works 10 P.M. to 8 A.M. as shift lead in the Global Network Operations Center, a place he likens to NASA's mission control. "When everything's going smoothly," says the easygoing 30-year-old, "mission control is happy." When there are crises, though--a telecommunications snafu in Africa, the disappearance from the wide-area network of a Microsoft office in a far-off city, provoking a cry like "Bombay's down!"--Scott transforms into a cyberspace fireman. Sometimes he resorts to the old-fashioned technology of the telephone, waking up the appropriate expert for guidance. Single, sandy-haired, and collegiate in jeans and running shoes, Scott realizes that staying up all night is not, well, normal. "Is man a nocturnal animal?" he muses. "Probably not." Come weekends, in order to play guitar with a jazz improv group and "stay in tune with my circadian rhythms, I go back to a normal schedule. I don't want to lose sleep, but I don't want to lose life, either."

The Baby Watcher Yvonne Harris, UAW-GM Child Development Center, Flint, Mich.

A child's land of nod, Yvonne Harris knows, has bumpy terrain. Having kept vigil over a room of sleeping children each weeknight for the past six years, Harris--a soft-spoken 40-year-old with no children of her own--eases those who uncomfortably stir. A child moans. "Kayla?" Harris calls. The girl's eyes flutter; she rolls over, goes back to sleep. "If they keep moaning, I check for fever and call the parents." The parents labor through the night at one of several General Motors plants in the vicinity. Some bring their children into Flint's UAW-GM Child Development Center when they begin an evening shift, then pick them up beyond midnight. Others drop them off at 4 A.M. before starting their factory day. "When I started here at night, I worried how I'd make it," Harris admits, telling how she had to care for a 3-year-old sleepwalker; how a storm one night woke the children, who huddled with her on the couch. Her tried-and-true method for putting a child back down? "A back rub," she says. There are other challenges, especially when the dozen or so children are tranquil and the music she plays makes her eyes heavy. "If I fall asleep, I lose my job." She has an unusual window on the local economy: "Last week one little girl just stopped coming. Her mother, I knew, had been laid off."

The Night Manager Walt Czarnik, Home Depot, Orlando

Beyond 2 A.M. on a mild Florida night, as parking-lot palms rise above flatbed trucks delivering stacks of lumber, Home Depot night manager Walt Czarnik--hair combed neatly, walkie-talkie on hip--lingers outside with watchful eye, then enters the 100,000-square-foot store. "Never let them see you sweat," he says, pacing the perimeter ("I figure I walk about five miles a night"), ensuring that all goes efficiently as associates forklift supplies onto shelves and customers hunt for sanders, weed whackers, and faucets. "We get emergencies this time of night," Czarnik says. "A bathroom pipe bursts, you rush in here." With night work in his background--in his 20s, at a truck plant in Detroit--and with his wife and one of his three sons having worked night jobs, Czarnik, 51, jumped at the chance to be top man on the 8 P.M. to 6 A.M. shift when the store went 24-hours two years ago, one of 103 Home Depots whose doors never close. "I'm security, bookkeeping, and sales." A deputy sheriff, his own nightbeat over, enters to buy a drill; a builder collects bricks and flowers to have a garden ready for a client by daybreak. "One woman," Czarnik says, "comes in a few times a week at 3 A.M. for garden mulch. Twenty years ago she would have been considered crazy. Now she's normal."

The Anchor Denise Dillon, CNN Headline News, Atlanta

Approaching midnight while looking fresh as noon, Denise Dillon peers into a robotic camera in the unsleeping CNN Center in Atlanta and talks to unsleeping millions. "I get a lot of letters from nursing mothers, older people who can't sleep, and second-shift workers getting home from work," she says on a break, adding that her mother, a factory worker outside Buffalo, where Dillon grew up, loves to tune in upon arriving home at midnight. Outside her glassed-in broadcast booth the newsroom is eerily quiet. A three-person crew in a studio behind her feeds text to a TelePrompTer and produces the 75 digitally recorded stories that will replay through the night, with Dillon adding updates. Dillon, who has been anchoring overnight for two years, attributes her vitality to physical fitness: She got married while running the 100th Boston marathon. Between her night work and her husband's day travel, they see each other mostly on weekends. But Dillon, who competes in Ironman competitions, makes the best of it: "After I sleep, I have the afternoon to run, bike, swim." She also enjoys being a step ahead of the information curve: "If I were dayside, I'd read the newspaper before I report about it."

The Astronomer Stephanie Snedden, Apache Point Observatory, Sunspot, N.M.

When twilight falls over the Sacramento Mountains, Stephanie Snedden dons her thermal suit, exits the Apache Point Observatory control room, and heads outside. There, she helps ready the Sloane Digital Survey telescope for another night of charting the heavens. "We're making a three-dimensional map of the universe," she says as the telescope's gargantuan eye opens to the sky, erupting with stars. Even though much astronomy today is conducted at computer terminals, Snedden, 50, who is completing a Ph.D. in astronomy, retains her sense of night's magic: "Out here the sense of night is primeval. You can imagine our distant ancestors sitting around the fire looking up at the night sky, generating myths, trying to figure things out in the first science." On nights off, Snedden sometimes ventures out into civilization's "light pollution"--3 A.M. grocery shopping at the 24-hour Wal-Mart in Alamogordo.