The first colonial landowner of the area that Mount Eagle would be built upon was a tavern owner, John Mathews, who received a land patent for 1,567 acres (6.34 km2) southwest of Hunting Creek in 1669.

His eldest son, Thomas, was executor of the estate, and began leasing out Mount Eagle with the first advertisement appearing in the Alexandria Gazette in 1806, placed by his cousin John Herbert.

[5] During the American Civil War, the Union Army began construction of earthworks on the ridge southwest of Hunting Creek after the defeat at the First Battle of Bull Run in July 1861.

[6] On 9 June 1863, a magazine containing 8 short tons (7.3 t) of gunpowder and several thousand artillery shells exploded in Fort Lyon, killing 25 soldiers, and shattering windows in nearby buildings.

Later that day Abraham Lincoln, President of the United States, arrived; he was accompanied by the Secretary of War, Edwin Stanton and Brigadier General John Slough, military governor of Alexandria.