The cache is not at the location you will visit. This is a field puzzle.  There is no code to solve or something to decrypt.  All you need to do is visit the location. Find some information and do simple math to find out the coordinates where the cache is located.  Please only visit during daylight hours.  Also, this location is in a housing community.  They are used to people visiting the fort who is interested in the Civil War.  And they also use the fort as a neighborhood park. (I can tell you of a time I was warned not to touch the easter eggs a neighbor across the street hid for their grandchildren)

Welcome to Star Fort

This is one of the best examples of earthen Civil War-era forts.

This hill on the north side of town had been used by both sides of the war to defend the town of Winchester, as it has a commanding view of the Valley road.  In 1862 the Union built more formal fortifications.  This was later improved by Union General Milroy into the current fortification you find yourself currently in.  Milroy built a series of fortification in 1863 before the Second Battle of Winchester,  What you see as you look around is an example of the fortifications built in the Civil War that follows the teaching of the American military theorist and CIvil Engineer Dennis Hart (D.H.) Mahan.  At the time of the Civil War, he wrote the book on defensive design for the American military as he taught many of the Pre War  West Point Officers that served. Below is a quick list of his books

• A Treatise on Field Fortification (1836)
• Elementary Course of Civil Engineering (1837; revised 1868)
• Elementary Treatise on Advanced Guard, Outposts, and Detachment Service of Troops (1847; revised, 1862)
• Summary on the Cause of Permanent Fortifications and the Attack and Defense of Permanent Works (1850)
• Elementary Treatise on Industrial Drawing (1853)
• Editor, with additions, the American edition of Mosely's Mechanical Principles of Engineering and Architecture (1856)
• Descriptive Geometry, as applied to the Drawing of Fortifications and Stereometry (1864)
• An Elementary Course on Military Engineering [covering] Field Fortifications, Military Mining, and Siege Operations (1865)
• Permanent Fortifications (1867)

Also, he is the father of A.T Mahan the renowned Naval Military Theorist.

So what you are seeing is a prime example of the earthen fort built during the war.  

Please enjoy your time here as you explore the fort looking for answers to solve this field puzzle.

N 39° AB.CDE W 078° FG.HIJ

To Solve for A & B find the below sign

Civil War Earthworks "Where they are compelled by nature ... to resort to it"

A = How many Degrees from Norwich University did Union Gen. Robert H. Milroy receive?  X - 2 = A

B = Look at the picture on the board of a copy of D.H Mahan Treatise on Field Fortification.  What was the last digit of the year it was published?  Please note this is the year that it was first published.   B = X

To Solve for C go to the set of stairs you used to enter the fort

C = How many time do you have to step up to enter the fort?  C = X - 1

To Solve for D & E find the following sign

Constructing Star Fort "It was hard work"

D = There is a quote for one of Milroy's Soldiers in a Conticut unit what number was the unit?  D = X - 14

E = What day of the month did Winchester resident Cornelia McDonald write in her diary about the home of former U.S. Senator James M. Mason being torn to be used for materials for Star Fort?   E = X - 20

To Solve for F & G find the following sign

Third Battle of Winchester "The enemy within the fort ... hastily evacuated"

F = Early ordered Col. Thomas T. Munford's brigade to Star Fort with Maj. James Breathed's Horse Artillery,  How many guns were in Maj. James Breathed's unit?   F = X - 1

G = A quote from a Pennsylvania Calvary Man is on the sign what is the unit number he was in?  G = X - 22

To solve for H find the sign

Second Battle of Winchester "The guns in Star Fort greeted them"

H = On what day did Early capture West Fort?  H = X - 6

To Solve for G find one of four benches at the Fort.

I = There are two words on the bench.  How many letters in those words? G = X - 5

To Solve for J find the sign

Second Battle of Winchester "A scene ... I shall never forget"

J = What is the middle name of the first Diarist quoted on this sign?  How many letters in her middle name?  J = X + 1