Nearly a century before Kevin Sumlin introduced the Swagcopter and Twitter hashtags to College Station, Texas A&M was still at the cutting edge of the recruiting game.

Harrison J. Allen, whose late great grandfather, Dr. Richard Henry "Chicken" Harrison Jr., played for Texas A&M as early as 1917, recently discovered a recruiting letter that then-Aggies coach Dana X. Bible sent to Harrison.

Written Aug. 20, 1919, Bible wrote to Harrison in hopes he would return to the A&M football team for the 1919 season. Allen said Harrison played for the Aggies in 1917 but not in 1918 as many members of the team served the United States in World War I. Harrison served in both World War I and World War II, and Allen said it is his understanding, though he's not 100 percent certain, that 1918 was one of his years of service.

"Every one is expected to put politics, business and even their best girl aside and report September 15th, for duty at College Station." 1919 Texas A&M recruiting letter

In the letter -- which Allen found in a scrapbook Harrison compiled in the early 1960s -- Bible requests that Harrison report for training camp and says that "Every one is expected to put politics, business, and even their best girl aside and report September 15th, for duty at College Station."

Allen, a 2011 Texas A&M graduate, said Harrison played quarterback, halfback, defense and drop-kicked field goals for the Aggies. The 1919 team went undefeated (10-0) and unscored upon, outscoring its foes a combined 275-0. Bible notes his high expectations in his recruiting letter, stating "I am convinced that the team that beats us will be the champion of the Southwest."

Nobody did.

Bible closed his letter by stating "This is the motto for 1919: 'They Shall Not Pass.'"

"It's truly incredible," Allen said of the letter. "I grew up attending Texas A&M football games more so than any other sporting event. When I saw the letter and read it a couple times, it took a minute to sink in how important it was. The fact that he actually recruited my great grandfather to come back and play and be a part of that undefeated and unscored upon team is quite remarkable."

Harrison graduated Texas A&M in 1920 and was among the first Aggies to earn a doctorate of veterinary medicine. He later became the team doctor for Texas A&M football for 25 years, which spanned the Aggies' 1939 national championship team and Paul "Bear" Bryant's coaching stint in College Station (Harrison is even named in Jim Dent's book, "The Junction Boys," about Bryant's legendary 10-day training camp in 1954).

History and tradition is a pillar of numerous college football programs across the country and those things are especially cherished at Texas A&M. Finding a tangible piece of that history has been particularly special for Allen.

"This letter was an incredible find for me," Allen said. "As a fifth-generation Aggie, I knew that my family had some remarkable ties to Texas A&M but this letter was a surprise."