The chirps of the endangered bird-voiced tree frogs were deafening - drowning out any noise trying to disturb the swamp.

And as a visitor ventured farther into the swamp, the cypress and tupelo trees seemed to close ranks, blocking from sight anything but the swamp. Suddenly, out of the isolation, a loud pop and a crash - a limb fell from a tree, and the sound echoed throughout the swamp.

Who would believe, that in the middle of this swamp, near Brinkley in rural eastern Arkansas, exists one of the most important places in American history?

A National Historic Landmark, preserved in the Louisiana Purchase Historic State Park, stands at the junction of modern-day Lee, Monroe and Phillips counties, 26 miles west of the Mississippi River. A granite marker remembers the initial point from which all surveys of the land acquired through the Louisiana Purchase were measured. “Ground Zero” was celebratedlast year on the bicentennial of the Louisiana Purchase.

President Thomas Jefferson in 1803 purchased from France 900,000 square miles of land in the New World for $15 million - less than 3 cents an acre - doubling the size of the fledgling United States. Arkansas and 12 other states would be carved from this area, which stretched from the Gulf of Mexico to Canada.

In 1815, President James Madison ordered a survey of the area - “a survey that began in what is now Arkansas and led to the settlement of the American West,” reads the Arkansas State Parks website. Prospect K. Robbins and Joseph Brown surveyedthe land.

“On Oct. 27, 1815, a survey party headed north from the confluence of the Arkansas and Mississippi rivers to establish a north-south line to be known as the Fifth Principal Meridian,” the website continues. “The same day, a party departed westward from the junction of the St. Francis River and the Mississippi to establish an east-west line, known as a baseline. The crossing of the two lines would be this initial point from which future surveys would originate” - the point preserved today.

Two more-contemporary surveyors, Tom Jacks and Eldridge P. Douglass, in 1921 discovered the gum trees marked by the initial surveyors in 1815. The L’Anguille chapter of the National Society Daughters of the American Revolution in Marianna placed a granite marker at the point in 1926, and 37.5acres became a state park in 1961. The Arkansas Natural Heritage Commission added it to the Registry ofArkansas Natural Areas in 1977, protecting “head-water swamp that represents a fast disappearing ecological setting in eastern Arkansas,” the state park’s website reads.

Today’s state park doesn’t offer anything fancy for visitors - just a latrinestyle bathroom and a beautiful, winding, barrierfree, 950-foot wooden boardwalk leading to the significant site. Along the way, signs interpret the history and the nature of the swamp.

Still, at the end of the boardwalk, looking down on the place nearly sacred, goosebumps raise on one’s arms.

The swamp itself also is a fascination for those living in mountains. It’s a head-water swamp: Ancient glaciers carved bowl-shaped basins into the land. The swamps are self-contained in the bowls. The water level rises and falls through the seasons, but the site seldom floods deeply and neverreally dries. Remnants of the floods seemed marked permanently on the venerable trees and the marker. Wildlife abounds in these wetlands. Many manners of birds, reptiles, animals and insects - mosquito repellent highly suggested - make this swamp their home.

Cotton and soybean fi elds surround the park, formerwetlands in the region were drained for flood control and agricultural development. This is the largest remaining head-water swamp in the Mississippi River Delta - and a jewel in the crown of Arkansas.

THIS IS ANOTHER IN A CONTINUING SERIES OF STORIES ABOUT UNIQUE PLACES IN ARKANSAS.

Life, Pages 6 on 02/05/2014