HARRIET TUBMAN started her Civil War more than 10 years before the first shots at Fort Sumter. Her first act of defiance was theft of property, and the first thing she stole was herself.

When rumors reached Tubman -- then a slave -- that she might be sold downriver to the hated cotton fields of the South, she fled for her life in 1849. She rode the rails, as the underground railroad expression went, on the first "boxcar" out of town. Though perilous indeed, there was nothing unusual about her run for freedom. By that point, the underground railroad was a well-established network of safe houses and secret passageways that spirited hundreds north to free states every year.

But what really distinguished Tubman's journey was not her flight but her return: Of the many slaves who fled Dorchester County, Md., on the underground railroad, Tubman was remarkable for hazarding more than a dozen round trips. She came back to her home county on the Chesapeake's Eastern Shore again and again throughout the 1850s to rescue at least 70 friends and family. Tubman risked her life and saved that of many others in daring forays that would earn her legendary status as "General Tubman" and "The Moses of Her People" -- not to mention a $12,000 bounty on her head.

Dorchester County now offers a self-guided driving tour highlighting the known historical landmarks of Tubman's life. The half-day tour takes in the county seat of Cambridge, the surrounding countryside of small farms and an occasional shimmering view of the Chesapeake Bay. Among much else you can see the courthouse where the Rev. Samuel Green was sentenced to 10 years for aiding Tubman's escapes, Tubman's childhood home on the land once known as the Brodess plantation and, most touchingly, the humble country churches where she prayed for freedom.

A slew of biographies attest to Tubman's indomitable courage, but in truth she was a most unlikely heroine. She was tiny, for one thing, standing only 4 feet 7 inches at maturity. Tubman also was sickly as a youth, sick enough that all attempts by her master to sell her to other slave owners met with failure. And then there were the manifestations of her epilepsy, thought to be originally caused by head trauma. Many would later recall conversing with Tubman only to find she had fallen fast asleep, sometimes for minutes at a time. She would awaken from her state and pick up the thread of their talk as if nothing had happened. These spells could occur as often as twice an hour.

The riddle of Tubman's extraordinary courage will never be solved, but the fount of her abiding outrage is easily apparent. Tubman was 6 when she was first separated from her mother and hired out to work on a succession of neighboring farms. (Her tasks included setting muskrat traps in the frigid waters of the winter marsh.) She was forced to continue working right through a case of the measles, becoming so ill she was sent home for a lengthy recovery. Later she was sent as a mother's helper to care for a baby and help keep house. Tubman was still so small herself she had to sit down to hold the baby. She was whipped if she was found sleeping during the night when the (very colicky) baby cried.

Perhaps the most indelible memory of Tubman's childhood, and the one thought to have brought on her epilepsy, was the incident during her teen years at the Bucktown country store (which still stands and may be seen on the driving tour). Tubman was buying food for her master's dinner when she saw a runaway slave being chased into the store by an overseer, who asked Tubman to help tie the slave down. Tubman refused, and in the ensuing melee, she was hit by an iron weight. The severe blow to her forehead left her incapacitated for months.

Paradoxically, it was this injury that was to pave the way for the epiphanies and religious visions that guided Tubman, she said, through her darkest hours on the underground railroad. She fervently believed in both the rightness and the inevitability of spiritual freedom preached in the African Methodist Episcopal churches of the day. (See Scott's Chapel and Bazzel Church, two of the churches where Tubman and the black community attended service, on the tour.)

It is the fate of folk heroes to leave no monuments or grand palaces behind, but traces of them are often hidden in plain sight. Tubman's traces can be found in the marshes and fens where she worked, the churches where she prayed and the black, snake-filled waters she forded in the dead of night. The Brodess farm is still farmland (although the estate is long gone), the Bucktown store where she received her blow still sits alone at the confluence of three winding country roads, and little Scott's Chapel, with a steeple sharp enough to jab anyone's conscience, still stands in an open field haunted by the cries of circling gulls. The landscape is old and beautiful, with all the serenity and benign potency that is the bay. But it's the sense of scale that ultimately inspires: that one so small, from a place so unknown, should have shaken the world so hard.

HARRIET TUBMAN DRIVING TOUR -- Take Interstate 495 to Route 50 east toward Annapolis. Cross the bridge over the Choptank River to Cambridge and take an immediate right onto Maryland Avenue to the Dorchester County Visitor Center (410-228-1000; www.tourdorchester.org). Pick up a Harriet Tubman Driving Tour brochure and map (indispensable) to local county roads.

The Harriet Tubman Museum and Education Center at 424 Race St. in Cambridge is under renovation but may be available for viewing by appointment. Call Evelyn Townsend at 410-228-3106.

Dramatic portrayals of events in Tubman's life are available for group showings. Call Vernetta Pinder, who portrayed Tubman in the Maryland public TV documentary "Crossings," at 410-228-8279. Harriet Tubman Tours (410-845-1285; www.mediavisions.biz) offers customized guided tours by appointment, a gospel program of slave songs as well as reenactments. For a general history and links to Tubman's life, visit www.harriettubman.com.

Harriet Tubman fled Maryland but returned to rescue others.A driving tour in Dorchester County, Md., gives visitors a peek at the life of escaped slave Harriet Tubman. Clockwise from top left: A teenage Tubman was hit with an iron weight at the Bucktown country store; a sign marks where her childhood home, the Brodess plantation, once stood; Tubman and others in the black community attended services at Bazzel Church; at the courthouse, the Rev. Samuel Green was sentenced to jail for aiding Tubman.