VALLEY FORGE is immovably fixed in the American mind as the symbol of the suffering and courage of the Continental soldier, even though the winter of 1777-78 was far from the worst of the Revolutionary War, and the army grew even hungrier and more ragged in later winter camps.

We rightly regard Valley Forge as the turning point because it tested the nation as it would not be tested again for another fourscore and several years. George Washington's small and fractious army limped into its bleak Pennsylvania encampment after defeats at Brandywine, Paoli and Germantown. Philadelphia, second-largest English-speaking city in the world, was in enemy hands, the many-headed American government was in disarray, and the fate of the democratic experiment was in the balance.

Six months later, after thousands of men had died but many thousands more had rallied to the cause, the Continental Army sallied forth and fought the British to a draw at Monmouth, N.J. It was far from the end of the struggle, or even the beginning of the end. But, as was said of such a day in a much later war, it was the end of the beginning.

More than four million people a year come to what is now Valley Forge National Historical Park, nearly twice as many people as there were in the United States in 1777. Some of the visitors come in the spring to see the dogwoods and some come in the fall when the leaves are turning. Most come in the summer, often just because they and it are there; Valley Forge is on the way to and from a lot of places.

The park is a lovely place to visit, except on a raw winter day. Which is why winter is the time to go there, if you are seeking some sense of how it was in that long-ago winter when the history of the United States of America could be written on a shingle.

In the soft seasons, the reconstructed log-and-mud soldiers' huts seem quaint, but a single hour spent in one on a January afternoon when the sun is a pale white wafer pasted on the sky will be instructive even to the warmly dressed visitor. It is cold in there, and dark. It is ugly. Of course, in the old days the chinking was better and they had a smoky, sputtering greenwood fire going, which kept the lice invigorated and the sometimes ankle-deep litter on the mud floor "smeling offal," as one disgusted Virginia soldier put it perhaps more precisely than he knew.

The soldiers were glad to have such huts, the alternative being tents or, as during the first few days, no shelter at all, sometimes not the half of a blanket, or even shoes. Although food and supplies had been assembled by state authorities and by the Continental Congress, there were not enough wagons to haul them to Valley Forge; and if there had been wagons, not enough horses to pull them.

When the first troops marched into camp on December 18, there was such confusion that many couldn't even find water to drink. Private J.P. Martin of Connecticut paid his last three pence for a swig from a passing soldier's canteen. Thereafter, he said,

I lay here two nights and one day and had not a morsel of anything to eat all the time, save half of a small pumpkin, which I cooked by placing it upon a rock, the skin side uppermost, and making a fire upon it. By the time it was heat through I devoured it with as keen an appetite as I should a pie made of it at some other time.

Early in the war most units were supplied by their mother states or even their hometowns, so that a Pennsylvania unit might be slurping milk and honey while Massachusetts men were starving across the way. Over the course of the six months, things more or less evened out, though; there was considerable sharing, willing or otherwise, among the comrades in arms, and before it was all over there was plenty of privation to go around.

As miserable as the physical conditions were, the harder test probably was spiritual. George Washington's army had been consistently outgeneraled, outmaneuvered and outfought in the months before it went into winter quarters, and had no reason to expect any different in the future. A soldier, lying hungry in filth and cold, had also to endure such memories as this one related by Private Elisha Stevens:

The Battel was at Brandy wine (September 11) it Began in the morning and Held til tonight with out much Seasation of arms Cannons Roaring muskets Cracking Drums Beating Bumbs Flying all Round, men a dying wounded Horred Grones which would Greave the Heardist of Heart to See Such a Dollful Sight as this to See our Fellow Creators Slain in Such a manner as this.

Our picture of Valley Forge is made up of such glimpses, seen through not only the fog of war but through the mists of time, not to mention the efforts of generations of Parson Weemses to sanctify the sometimes bawdy, venal and perverse Founding Fathers and the often greedy, brutal and cowardly Freedom Fighters. Even original sources aren't much help. To one loyalist, the Continentals were "A vagabond Army of Raggamuffins, with Paper Pay, bad Cloathes, and worse Spirits." But an admiring army doctor at Valley Forge said "the barefoot soldier labours thro' the Mud and Cold with a Song in his mouth extolling War & Washington."

Desertions averaged at least a dozen a day and probably many more, although the smaller number would amount to something like a fifth of the army. It's difficult to assign hard figures to anything about Valley Forge because various authorities vary wildly in their estimates of everything from the peak strength of troops present (less than 10,000 to more than 20,000), to the number who died (2,000 to more than 7,000, including sick men sent to outlying hospitals). Even the best guesses as to the number of huts in the encampment run from 800 to more than 2,000. All this in spite of the countless scholar-years of research funded for the Bicentennial.

What is clear is that the Continental Army was transformed between December 1777 and June 1778. What straggled into camp was at best a coalition of units with little in common but the common cause. What marched out, sixth months later to the day, was an army that had learned drill and discipline without forgetting that its members were free men and that to keep them free was the point and purpose of it all. (There also were hundreds if not thousands of slaves serving as combat troops, nearly all of them from New England. They had been promised their freedom when honorably discharged, and most of the white soldiers, even those from Southern states, spoke of their endurance and performance with at least grudging, and often unstinting, admiration.)

The credit for the transformation lies, first, with General Washington. As a soldier he was even less of a tactician than he was a strategist, but he was, simply, a Great Man, one of those semi-mythical conjurors who can make bricks without straw, inspire self-sacrificing love, and shape the future by force of will. He'd been repeatedly defeated, was desperately short of everything and was distracted by an effort to replace him as commander-in-chief, but held it all together by the power of his personality and the awe inspired by a dignity so natural that he could, and often did, take a turn at bat in camp cricket games without anybody being in the least danger of mistaking him for one of the boys.

If Washington kept the army going, the man who taught it how to march and fight was Lieutenant General Friedrich Wilhelm August Heinrich Ferdinand, Baron von Steuben, late officer of the army of Frederick the Great. In fact this Prussian parvenu was not a lieutenant general, not a baron, and not even a Steuben (his daddy, name of Steube, had added the final n to imply a connection with an aristocratic family).

He was just an out-of-work and nearly bankrupt army captain who couldn't even speak the language of the commander to whom he offered his services. It is wonderfully symbolic of the American experiment that this phony was promptly put in his proper place, which was Inspector General, in charge of all troop training.

Steuben was as irascible as he was energetic, and it is said that the first two English words he learned were a) God, and b) damn. His roaring echoed the length and breadth of the great central drillground, known as the Grand Parade. Steuben got on everybody's case, tongue-lashing company and field-grade officers along with their men. A product of the Old World's most rigid aristocratic tradition, Steuben put the New World democrats to shame by his hands-on, man-to-man involvement with the troops. An officer has to care for, and about, his men, asserted this bouncy, witty and altogether irresistible martinet. The Continental officers, who tended to look down their upper- class noses at the commoners they commanded, were scandalized. But who could argue the point with a man of royal blood who had been a ranking general in the most professional army in the world? And so, like Steuben, they began to practice the manual of arms and to march, studying the simplified new training manual Steuben wrote to keep a lesson or two ahead of the troops. Later they led instead of sent them into battle. The following books were among the sources used in preparation of this article and are available at the bookstore of the Visitor Center at Valley Forge Park. PRIVATE YANKEE DOODLE -- by Joseph Plumb Martin (Eastern Acorn Press, 305 pp., paper, $1.95). The lively, colorful and straightforward recollections of a Connecticut Yankee who served throughout the war. A REVOLUTIONARY PEOPLE AT WAR -- by Charles Royster. (W.W. Norton & Co., 452 pp., paper, $9.95). This is not revisionist history, exactly, but neither is it the sort of sanitized pap served up in school. It's a gold mine of the things Teacher never told us, with a nugget in almost every paragraph. Good illustrations, and lots of them. VALLEY FORGE: CRUCIBLE OF VICTORY -- by John F. Reed. (Philip Freneau Press, 76 pp., cloth, $11.95). This book is somewhat disappointing because the large format is not used to advantage for illustrations. But the relatively brief text is penetrating and unflinching. BIRTHPLACE OF AN ARMY -- by John B.B. Trussell Jr. (Pennsylvania Historical and Museum Commission, 145 pp., paper, $4.95). Trussell probably knows more about Valley Forge than anyone else; he's put an awful lot of it in this slim paperback, and in very readable fashion. THE PENNSYLVANIA LINE -- by John B.B. Trussell Jr. (Pennsylvania Historical and Museum Commission, 368 pp., cloth, $11.75). This volume is specifically about Pennsylvania's role in the war, and while Trussell may tell you more than you really want to know about it, this is wonderful stuff. DIARY OF A COMMON SOLDIER IN THE AMERICAN REVOLUTION -- by Jeremiah Greenman (Northern Illinois University Press, 333 pp., paper, $9). Kept by a Rhode Island soldier throughout the war, this diary was not intended for publication and is difficult to read even though (and sometimes because) it has been heavily annotated by editors Robert Bray and Paul Bushnell. But a sense of the man, the times and the war rewards patient reading.