POISED on a soaring bluff above the Potomac River, not far from Virginia's Popes Creek, is Stratford Hall, one of the great residential landmarks in American history.

The visitor who enters the gate at Stratford is driving over the same road used by the family of patriots called the Lees, two of whom grew up to be the only brothers to sign the Declaration of Independence.

Four generations of Lees were born in a big upper-floor bedroom. A tiny net-draped cradle sits by the window, on the spot where it once rocked the infant Robert E. Lee, destined to head the Armies of the Confederacy.

The mansion was built in the 1720s by Thomas Lee, a prominent planter who had a stint as acting governor of Virginia. Five of his six sons played major roles in the Continental Congress.

This familial devotion to duty took root on what was then a plantation of 30,000 acres. Farming and milling take place today on 1,600 of the original acres. At the Stratford Store, you can buy bagged oats, corn, wheat or barley, ground in a waterwheel mill as they have been for centuries.

And James Monroe's birthplace is a 10-minute drive from Popes Creek. Although there is nothing except a sign, the land was recently purchased by the Association for the Preservation of Virginia Antiquities, and can be seen along Va. Rte. 205 toward Colonial Beach.

The birthplace of James Madison is at Port Conway on the Potomac, and is commemorated by a sign on Route 301.

You might leaf through the following books before you explore this famous road: "American Colonial Mansions" by Everett B. Wilson; "Homes and Gardens of Old Virginia" edited by Frances Christian and Susanne Massie; and "Planters and Pioneers, Life in Colonial Virginia" by Parke Rouse Jr. GETTING THERE -- Follow Route 301 to VA 3. Turn left to Lerty and make a left on Route 214 to Stratford Hall. Open 9 a.m. to 4:30 p.m. daily except Christmas. $3 for adults; $1 for children under 16; free for children under 6; group rates available. 804/493-8038.