There's a saying at Lincoln University: "White by day, black by night."

A hilly, picture-pretty campus with 3,343 students enrolled this fall, Lincoln was founded by black Civil War veterans. It was once revered as the black Harvard of the Midwest. Today the school is 70 percent white. Yet when night falls, many whites clear out.

Blacks dominate the dorms, the frats and sororities, most social activities and, after graduating, the alumni association. Whites, a presence since the 1950s, complain they feel unwelcome. Some, like Heather Raithel, prefer the unofficial white student union--a study hall in a building named for the Rev. Martin Luther King Jr.

There's little evidence of tension. It's more polite avoidance.

"They're over there, and we're over here," said Raithel, 21, an elementary education major.

Decades after segregation was outlawed, it persists at Lincoln. Only now, it is not laws but a social wall that separates people. That wall, built by history, is buttressed indirectly by tax dollars.

Lincoln is among the nation's 105 historically black colleges and universities and endorsed as such by the federal government. HBCUs, as they are known, serve 280,000 students in 20 states, the District and the U.S. Virgin Islands. A legacy of slavery and legal segregation, the schools are recognized for their continuing mission to educate African Americans. About 70 percent of students are at state-supported HBCUs like Lincoln, though a majority of the schools are private.

The schools receive special funding--$180 million in current federal budget. The money is provided under a law Congress enacted in 1965 to protect and promote HBCUs' "unique role of educating black, educationally disadvantaged, and low-income students."

Yet at least 15 HBCUs now educate a sizable white enrollment.

Lincoln is one of three where blacks are the minority. But it reflects a trend that ranges from historically black Bluefield State College in West Virginia, where blacks now make up just 9 percent of 2,400 students, to Winston-Salem State University in North Carolina, where 80 percent of 2,800 students are black.

Reasons vary. Blacks have more choice. Geography plays a part. Stigmas fade. Civil rights lawsuits are pressing some HBCUs to raise white enrollment, just as traditionally white schools must bring in more blacks. Tennessee State University must produce 50 percent white enrollment under a 1984 court order. It is now less than 20 percent.

The U.S. government also pushes states to put their public black colleges and universities on equal footing with traditionally white ones--so that they are academically indistinguishable.

No racial quota is needed to maintain special federal funds. But federal officials notice the shift.

"That is a developing policy issue," said Claudio Prieto, acting assistant secretary of education for higher education. In a recent interview, he said no funding change is planned.

What about places like Lincoln, divided over their identity?

"In a very general sense, if people wish to segregate themselves, should the government support it or fight it? The answer is I don't know," Prieto said. "It depends on who the people are, and the factors going on around them."

It was once a crime in Missouri to teach a black person to read and write. When black Union veterans donated more than $5,000 to establish Lincoln in 1866, some could not sign their names.

Industrial skills were stressed then, along with study. But by early this century, as Missouri's only four-year public college open to blacks, Lincoln rose to prominence with faculty educated at Harvard, Columbia, Cornell.

Until 1954, when the Supreme Court ruled segregated grade schools illegal, Lincoln was all-black. Within months, Lincoln's board of curators voted to admit whites.

Hazel Birth graduated from Lincoln in 1954. She stayed and saw the world change.

"That summer we had an influx," said Birth. The retired guidance counselor in Minneapolis recalls white women arriving in shorts, smoking--shattering Lincoln's then-strict rules. Faculty were silent, she said. "It was like they were almost afraid to offend them."

Lincoln, Birth said, "was going to hell in a handbasket."

Yet delight softened her alarm. "I felt, 'Hey, we have something that they want.' "

In those years, Lincoln students mixed freely in social activities. Whites joined black students trying to integrate Jefferson City's bowling alleys, movie theaters and restaurants.

"It was new," Adrienne Hoard, class of '70 recalled. "In the '60s, people were more open to do the uncomfortable."

Hoard, who is black and teaches fine art and art education at the vast and vastly richer University of Missouri 30 miles north, laments it did not last. "Society is still segregated," she said. It's no wonder Lincoln students don't mix well. "We're asking these institutions to do things the society has not done."

The '60s also brought chaos to Lincoln. Fire during a protest in 1969 gutted the student union. "We shall overcome" dissolved into "You go your way, I'll go mine."

During homecoming this October, the student union at Lincoln served an Alumni Soul Food Dinner. The dining hall buzzed with students and returning grads, not a white face among them.

Audrey Ford, an 18-year-old freshman from Detroit, took small comfort in this friendly scene. Whites fill Ford's classes; white faculty teach them. Just 22 percent of the 161 full-time faculty is black.

"I'm proud to have black founders," said Ford, who chose Lincoln over the University of Michigan. "Proud to have something we founded and still, kind of have." She added glumly, "We're a minority now."

Today, amid Lincoln's modern towers, once-stately brick buildings stand shuttered in disrepair. Never well-endowed, the school operates on a $37 million budget. Its biggest funding sources in fiscal 1999 were $15.6 million from the state and $9.8 million in federal funds. Student fees and tuition contributed $7.2 million.

Yet more than ever Lincoln remains a magnet for whites. Located in the state capital, a city of 35,000 in Missouri's rural middle, the school's $92 per credit in-state tuition is a bargain. The typical undergraduate pays around $1,500 a semester. Compare that to $132.60 per credit and $2,300 a semester at the University of Missouri-Columbia, with 22,500 students.

Add low cost to small classes, easy access to professors and open admissions and Lincoln easily attracts ambitious whites and blacks with modest grades and test scores, and little money.

They have a lot in common. But many cannot see past surface differences, starting with where they come from.

Most of Missouri is white. Blacks, about 11 percent of state residents, live mainly in the big cities of St. Louis and Kansas City.

The favorite explanation for Lincoln's social segregation is that whites "commute," living with parents or young families, often holding down jobs with little time to play. Black students live on campus because their homes are hours away. The two groups diverge in musical tastes, language, mannerisms. But Lincoln's administrators and some students are trying to change this.

Students take a required cultural diversity course. That spawned a group two years ago called Barrier Breakers, students and faculty who stage events like poetry coffeehouses that appeal to all students. There are plans to offer whites a scholarship to encourage more to live in the dorms; currently only 25 to 30 whites live among 579 dorm residents.

"We have to deal with the realities that, like it or not, we still have a largely segregated society," said Lincoln President David Henson. His priority is turning out well-educated people. "I would love for there to be the day when we didn't have race-specific anything."

In the face of demographic reality, Lincoln clings to its first purpose.

During homecoming, Henson sought to reassure a roomful of anxious black alumni.

"This is a multiracial university and it will be into the future," Henson, himself a product of HBCUs, told them. "But we will not back off," he said. "We are ready to help those black students, just like those black soldiers."

Like single-sex and religious schools, HBCUs appeal to students more at ease and better able to learn among people like themselves.

More than that, educators say, many blacks still face exclusion from mainstream classrooms.

"We have developed other ways to keep persons out," said Henry Ponder, president of the National Association for Equal Opportunity in Higher Education, which represents historically and predominantly black schools. "Before, it was just plain color," Ponder said. "Now we use test scores, essays, who their parents were."

Though a small segment of U.S. higher education, where 4,000 institutions educate 14.5 million people, historically black schools present an appealing option for many of the 12.8 percent of Americans who are black.

Studies show that while more blacks attend mainstream schools--only 16 percent of black students were enrolled at HBCUs in 1996, for example--blacks attending historically black schools are more likely to complete their degree, earn an advanced degree and make as much or more money than those at traditionally white schools.

Better known HBCUs include Tuskegee, Grambling, Morehouse, Spelman, Fisk and Howard University, chartered by Congress in 1867. There's also another Lincoln University, in suburban Philadelphia and founded in 1854.

These schools reflect reality, as well as a need.

"Desegregation really never happened, in any level of education," said Kimberley Edelin Freeman, head of research at the United Negro College Fund. But unlike students in public school, she said, college students have a choice.

Homecoming week at Lincoln, Nathan Otto bent over his books, bathed in sunlight that streamed through windows at Lincoln's new $11 million library. Otto, 20 and a farmer's son, plans to become a veterinarian. He lives on the family farm 50 miles away in St. Anthony. Lincoln was "cheapest, and it's close to home," he said. His dad objected at first, not saying why.

Otto likes the school and its small classes, but avoids Lincoln's social life. He lives too far away to return on weekends to party. Farm work and a convenience store job also keep him away. Fraternities do not interest him. "From what I hear, most white people don't go to fraternities," he said. He wouldn't even try. "I'd feel unwelcome . . . I just go to school, put my time in."

Studying nearby in the same sunny spot, Kirsten Collins, 19, said Lincoln's segregation dismays her. On a break from her library job, the future nurse, who is black, said blacks and whites mixed more at her high school in Columbia. She misses that. "Everybody needs to grow from each other."

Collins tries. But when white friends told her they would skip homecoming--even with the return of football after 10 years--she had no comeback. "I don't know if they thought it was geared more to black things," she said. "But who's to say what are black things, what are white things?"

White students who venture into the black social scene, leaving fear and bias behind, can find friendship. Emily Hatcher is one of those white "commuters." She lives in town with her parents and holds down a job. When the 18-year-old joined the band with her French horn, she was one of three whites in a crowd of 88 people.

Black students were eager to get to know her. "They came up to me and introduced themselves and were very, very sweet," she said. Now they go to movies and hang out together.

And at the Alumni Soul Food Dinner, seated across from the disappointed Ford was Marguerite Boyce, a still-enthusiastic graduate of Lincoln's class of 1945. The retired librarian, who lives in Detroit, was ecstatic when her granddaughter, Danielle Fitzhugh, 18, enrolled at Lincoln.

Fitzhugh, also from Detroit, plans to become a corporate lawyer, so she's glad to be immersed among whites, as her career will be. "I didn't want to be in a school that was one certain group," she said.

But like Ford, the 76-year-old Boyce was bothered when whites became the majority at her beloved alma mater. "At first I had pangs. 'Now you want to take our school?' "

That view was selfish, Boyce said. "It's not about race. It's about opportunity."

CAPTION: April Koch, 20, of Meta, Mo., cheers for Lincoln University football team. She is one of few white band members at the school, where enrollment is 70 percent white.

CAPTION: Students and alumni talk at Alumni Soul Food Dinner during homecoming week at Lincoln University. The campus suffers de facto segregation as whites and blacks generally avoid socializing. Most white students live off-campus.

CAPTION: Lincoln University President David Henson, 61, speaks to alumni during this fall's homecoming weekend.