OUT IN middle America, where the land lies flat and rivers run slowly, stands my hometown: Springfield, Ill. I left there 25 years ago, going east to become a teacher and writer. In 1958 Springfield did not abound with ideas or culture. I was forbidden to read "East of Eden" in study hall, and a librarian refused to lend me "The Portable Aristotle."

Recently, the class of '58 from Springfield High School held its 25th reunion, and I decided to attend. Pulled by sentiment and curiosity, I joined others who came from Massachusetts, Texas, California and Florida to converge upon the town we had called home.

Our class vice president reminded us of the passing years. Once a lithe athlete, Jack Billington is now a lawyer of generous proportions and gleaming pate.

He gave a deposition on those days in '58, "when Kareem Abdul-Jabbar was Lew Alcindor (and 3 feet 6 inches tall) . . . when gas was 15 cents a gallon . . . and the handle bars on bikes pointed up."

We heard telegrams from distant classmates and remembered 10 who were gone forever. Two cheerleaders, still trim and pert, led us through the chant that inspired our warriors: "S-U-C-C-E-S-S" (Hey!) Is the word that spells SUCCESS (Hey!)."

We did not talk of Success that night, but rather of Survival. After 300 months, as Jack reminded us, we had seen glad times and bad, but somehow we prevailed. We represented 40 states of the Union, many lines of work. I spoke with a surgeon, a fireman, and a leader of the band; with too many lawyers and not enough teachers; with an artist in stained glass and another in dentures; with people who had held many jobs and one who never tried any. (He clips contest coupons; last year he won a new Maserati.)

Success is fickle; it rarely comes when we most want or need it. Many of us left Springfield to chase our rainbows elsewhere, and I wondered how the town looked to its far-travelers after all those years. The answer that I often heard was, "Not bad, not bad at all."

Some days after the reunion, I went to see my old neighborhoods and revisit local sites of interest. I could tell how old I've grown, from the size of trees along the parkways. All the former saplings are now tall and sturdy, spanning the streets in a thick canopy. I saw new houses, in once empty lots, and old houses--that I had remembered as new. But most schools and churches are unchanged, and the streets are still paved with century-old brick.

Springfield is a town of history and poetry, struggling always to remain prosaic. Its commercial products--corn, coal, coffee brewers and electric meters--are sold everywhere. But the legends this place gave to America are more enduring: Abraham Lincoln, Vachel Lindsay, John L. Lewis, Adlai Stevenson--whether in triumph or failure, they shaped our national principles.

So did other, forgotten, martyrs. The Donner party left Springfield in 1846 to cut a new trail to California and perished in the effort. Four black citizens were lynched in Springfield during a race riot in 1908; within a year their deaths were to spur the creation of the NAACP.

Racism was common in Lincoln's hometown, for Springfield stood on divided ground. The old Mason-Dixon line ran just five miles south, and early settlers were either Yankee or Southern. Lincoln himself married a Kentucky belle; local opinion holds that it was she who taught him to savor emancipation. Lincoln has been called "the most durable ghost in American life," and he certainly is for me. I grew up on the legend of that log cabin boy, who read by firelight out at New Salem and walked miles to return a book. But too much of this folkore makes him a plaster saint, as attested by the local tendency to call his home and tomb "shrines."

Since 1971, federal regulations have made Lincoln's birthday a movable feast (first Monday in February) and his home a National Historic Site. The latter change has considerably altered 8th and Jackson streets. The Lincoln home is restored to near reliquary status with every detail, from carpets to curtains, attested by historic evidence. Outside, the National Park Service has converted two blocks of 8th Street to an 1850s look; gas lamps and board sidewalks, house lots enclosed by plank fences. The effect seems fidelity itself, including some flaked paint and dry rot that has appeared since the advent of Reaganomics.

The Illinois State Historical Society runs a more elegant show at Lincoln Square, where the Old State Capitol was restored to perfection in 1969. This building looks as though its occupants had suddenly disappeared, on a day in the 1840s. Papers lie tumbled on senators' desks; cloaks and hats still hang in the corners. Here Lincoln served as a legislator and lawyer. He debated bills in the assembly, where a stove-pipe hat marks his desk, and pleaded cases before the state supreme court--a room in which justice was blind, for the chief magistrate sat squarely behind a pillar.

At 6th and Monroe stands the Lincoln-Herndon Building, where Lincoln rented law offices on the third floor. Privately owned, these rooms and exhibits are in a frowzy condition, but I found this atmosphere suited to the years when Lincoln made money but held no public office. In these cramped, airless quarters, where the floorboards creak and book bindings crumble, I easily could imagine him on a slow afternoon, stretched out on a table and swapping yarns with his partners, Logan Hay and Billy Herndon.

Springfield said farewell to Lincoln at the Great Western Depot, where he delivered a remark the town remembers fondly: "To this place, and the kind news of these people, I owe everything." Today the depot owes its survival to the Illinois State Journal-Register, which maintains a slide show that recreates the President-elect's journey to Washington. Lincoln's words (spoken by his editor, Roy Basler) to crowds along the route invoke his stirring vision of the Union. At Trenton, he recalled the colonists' struggle for "that something even more than National Independence"; in Philadelphia, he praised "that Declaration giving liberty not alone to the people of this country, but hope to the world for all future time."

Four years later, a train bore Lincoln's body home to Springfield. The town laid him to rest in Oak Ridge Cemetery. The mausoleum later erected there is in the grand Beaux Arts tradition, a soaring obelisk with heroic sculptures, but one inscription is a proper tribute to Lincoln's simple dignity: above the tomb are the words spoken at his death, "Now he belongs to the ages."

Springfield found Lincoln a hard act to follow. A town that has raised a national hero should not tolerate saloons, casinos, and brothels in its midst, at least not according to its many reformers, local and national. Billy Sunday, the ball player turned evangelist, preached revival at First and Adams for 40 days and nights in 1909; he left behind 4,000 converts and took away nearly $20,000 in untaxed profits.

More permanent reforms followed changes in government structure, reports by national foundations, and the election of honest officials. Today the old redlight district, Washington between 6th and 8th, makes for a tame walk, indeed, past landscaped insurance offices and a new convention center--now playing host to 6,000 Jehovah's Witnesses.

Vice never disappears, it just takes new forms. Triple-X movies are playing at the local drive-ins; a nightclub called 'Nferno announces a contest for "Miss Nude Springfield." But manners and mores are about the same as elsewhere: the day's published record of vital statistics is 13 births, seven deaths, 11 marriages and 24 divorces. Also eight building permits, mostly to tear down old structures.

To find the essence of life in Springfield, I turned to its phone book pages: one page for taverns, four for churches, 15 for restaurants of every description. The town has come a long way from its early cuisine, corn bread baked on a hoe (hoecake) and bear meat fried in maple syrup. Today's bistros still go for heavy fare, while churches and clubs offer the All-You-Can-Eat versions of fish fry and pig roast, along with annual pancake breakfasts, chili or burgoo suppers, and ice cream socials.

Burgoo is one of two foods indigenous to this area; the other is horseshoe sandwich. Both adopt the culinary principle of me'lange: the horseshoe combines eggs, toast, ham and fries in a rarebit sauce; burgoo is a stew of simmering vegetables and game--generally coon, squirrel, and rabbit. For lighter appetites, I can recommend The Feed Store on Lincoln Square, where customers sit amid banks of fern and dine on yogurt or sprouts.

Springfield always has had a gentler, more cerebral side, exemplified by its sad star-dreamer, the poet Vachel Lindsay. His home, at 5th and Edwards, is open for tours by appointment. Until recently, the guide was a legendary high school teacher, the late Elizabeth Graham. Miss Graham made Lindsay come alive, recalling his hobo tours of America, when he preached "the Gospel of Beauty." She also played records of his recitations, in which he sounds like a tired old ham.

Lindsay had a mystical faith in democracy, and he believed that Springfield was the western city that could fulfill the historical destiny of America. In a visionary tract called "The Golden Book of Springfield," Lindsay tried to fuse his socialist politics with a militant Christianity. The ideas were far beyond his time, his town, and even his own capacity to express. Wasted by speaking tours, he wrote little in his last years and took his life at 52, by drinking poison.

Lindsay never saw the building of his city's most beautiful and useful public project, Lake Springfield. Opening day ceremonies in 1935 would have pleased him, as vials of water from the world's oceans and seas were poured into the new lake. The impounded water gave Springfield a new reservoir, recreation, and a source of energy. Today the City Water Light and Power Company at Spaulding Dam is the largest municipally owned electric utility in Illinois, a rare instance of socialism in a staunchly capitalist town.

Springfield has changed greatly since I left in 1958; now it has three colleges and a state university, a fine public library--stocked with Steinbeck and Aristotle. The town also has a ballet company, classical music station and a store called Prairie Archives, offering rare books and prints. Most of what I left to seek has found Springfield in turn.

On bad days, I used to retreat to Washington Park, a haven of guaranteed solitude. Today the park is jammed with all sorts of celebrants--walking, jogging or racing bikes. Girls are playing fast-pitch softball; boys are rehearsing for a dance recital at the Rees Carillon. Even the lawyers are running, in a five-kilometer race called "Ambulance Chase".

Many of these changes have swept the Midwest, as its staid ways yielded to more open styles of living. But Springfield was named an All-American-City by Look magazine in 1969 because the town turned around, began to improve its race relations and housing conditions, to attract new businesses and young, educated families. One of the chief movers and shakers in that era was Mayor Nelson Howarth, a farsighted and tough-minded man, whom I have the good fortune to call my father.

Springfield will continue to have a bright future, as long as it looks squarely at its past. That seems to be happening at the newest historical site in town, the Dana-Thomas House at 4th and Lawrence. Built by Frank Lloyd Wright in 1904, the house is a prime example of his early Prairie style, in which he designed every window, table and lamp according to a unified plan.

Moving through these rooms, I still could look out at ordinary Springfield--plain little cottage houses, perched near a railroad track. Wright's house was dark inside, too severe and sculpted for comfort. I wondered how one dusted such a place, kept it warm or cool. And I realized that I was thinking like a local.

It was time to say goodbye, but perhaps not for another 25 years. I hear that '58 already is planning our 30th reunion.