The papers of the Gibson-Getty-McClure families span the years 1777-1926, with the bulk of the material concentrated within the years 1880 to 1901. The collection is primarily composed of correspondence supplemented by diaries, financial papers, and miscellany.

The papers focus on the lives of three families from Cumberland County, Pennsylvania, each with a tradition of military service on the part of some of its members. The families are interrelated through the marriage of Margaretta Gibson, daughter of John Bannister Gibson, former chief justice of the Supreme Court of Pennsylvania, to Charles McClure (1804-1846) and through the marriage of their son, Charles McClure to Annie Getty, daughter of George Washington Getty.

The Gibson family papers, 1777-1854, the smallest segment in the collection, mainly concern the efforts of the heirs of Colonel George Gibson (1747-1791) to secure commutation pay from the state of Virginia for his military service during the Revolutionary War. Correspondence includes letters exchanged between John Bannister Gibson and his brother, General George Gibson; two letters of John B. Gibson to his wife, Sarah; and letters of his daughter, Annie, including one coauthored with her brother, George, describing the last days and eventual death of their father. The remaining letters and documents in the Gibson family papers relate chiefly to the verification of Colonel George Gibson's military service.

Although George Washington Getty’s papers extend from 1847 to 1913, they contain little information about his life before 1858. Family letters generally discuss financial matters, family news and acquaintances, social events, and items of general interest. Getty's brother, Gardiner T., and his son-in-law, Charles McClure, who managed Getty's business affairs, are the principal correspondents in the early letters, but most of the later letters are from Getty to his wife. Two letters from Getty's son, Wilmot, and a few letters from William McClure, who succeeded his brother as Getty's financial adviser, are also in the family correspondence. The general correspondence consists chiefly of routine military communications and letters concerning Getty's financial affairs, but also includes a letter reporting the capture of Hills Point battery in 1863 and letters written in 1868 concerning Getty's involvement in operations against Native Americans. In addition the Getty papers contain sporadic letters between 1878 and 1882 bearing upon the reinvestigation of the Fitz-John Porter court-martial and correspondence in the 1880s concerning the struggle of senior army officers to gain recognition for their Civil War service.

The papers of Charles McClure, 1849 to 1926, are the most extensive group of papers in the collection. McClure's career in the military carried him to various posts across the country and to the Philippine Islands during the Spanish-American War. Some of his travels and observations are recorded in his two diaries. The first, covering a trip from Santa Fe to forts in the southeastern United States between February 23 and March 29, 1867, contains accounts of army life on the frontier just after the Civil War. The second diary, relating to McClure's service during the Spanish-American War, details circumstances surrounding the execution of his duties as paymaster en route from Chicago to Atlanta and then to San Francisco where he completed financial arrangements for transporting necessary funds to the Philippines. Also included are accounts of his voyage to the islands and descriptions of military action there.

McClure's letters to his relatives discuss family matters and social obligations, comment on military operations, depict life on army posts and in surrounding towns, and in general reflect the impact of a military career on the private life of his family. Letters exchanged between McClure and his mother, Margaretta Gibson McClure, and letters to his wife, Annie Getty McClure, dominate the first part of the family correspondence which also includes letters from his brother, William, his aunts, and a host of cousins. As McClure's children matured, their letters assumed a more proportional share of the correspondence. For the most part, letters in the general correspondence concern the performance of McClure's duties, first as commissary and later as paymaster for the army. Typescripts of letters from Annie McClure to a friend in Georgetown, D.C., in the years 1868-1870 describe the town of Santa Fe and life at a frontier post during the latter half of the nineteenth century.

Correspondents in the Gibson family papers include John Bannister Gibson, his children, Annie, George, and Margaretta, and his brother, George Gibson. Prominent individuals writing in the George Washington Getty papers are mainly military officials and include Ambrose Everett Burnside, Ulysses S. Grant, R. H. Lamson, John Pope, William S. Rosecrans, John McAllister Schofield, Philip Henry Sheridan, William T. Sherman, and Hazard Stevens. John Rutter Brooke, A. B. Eaton, Francis B. Jones, and William Beatty Rochester are among the correspondents in the McClure papers. Family members represented in McClure's papers include Fannie M. Gibson, Charles McClure, Jr. (1875-1901), George McClure, Margaretta Gibson McClure, and William McClure..