This collection consists of 9 volumes of correspondence which documents Pepper's role in expanding the University of Pennsylvania in the 19th century, his contributions to the medical profession and his activism in Philadelphia. His papers are arranged chronologically and contain letters of his appointments to various positions within the University of Pennsylvania, culminating in his appointment as provost in 1881; as attending physician at various hospitals through out the city; and to numerous boards and clubs. Also included are writings, speeches, biographical material, medical notes on patients, newspapers clippings, reports, programs and invitations. The bulk of his papers while serving as Provost are found in the University of Pennsylvania Archives and Record Center. It should be noted there is no family correspondence except a few letters to his wife from her brother.

William Pepper was born in Philadelphia on August 21, 1843, the second son of William and Sarah Platt Pepper. William Pepper attended the University of Pennsylvania where he earned his bachelor degree in 1862 and graduated Valedictorian of his class. Following in the footsteps of his father and older brother George, he attended medical school and received his medical degree in 1864 from the Medical School at the University of Pennsylvania.

Dr. Pepper began his medical career as a visiting physician at the Philadelphia Dispensary in 1864. The following year he was appointed resident physician at the Pennsylvania Hospital. He became affiliated with a variety of hospitals in the Philadelphia region through out his career. He was appointed a lecturer at the Medical School of the University of Pennsylvania in 1868, where he taught Morbid Anatomy until 1870. He was transferred to the Department of Clinical Medicine and lectured on that subject until 1874 when he was elected to a full professorship. It was also during this period that Dr. Pepper was instrumental in establishing the Hospital of the University of Pennsylvania (HUP).

In 1881, Dr. Pepper was unanimously elected the eleventh Provost for the University of Pennsylvania. A post he held for thirteen years until his retirement in 1894. During his tenure, a few of his accomplishments included expanding the required medical course from three years to four; establishing the Wharton School of Business and the Graduate School of Arts and Science; increasing the size of the faculty and student body; and laying the groundwork for the Graduate Department for Women. He also contributed personally to the University by donating funds for the William Pepper Laboratory for Clinical Medicine, the Pepper Professorship of Hygiene Fund, and the William Pepper Medical Library Fund.

In addition to his work at the University of Pennsylvania and his private medical practice, Dr. Pepper was active in several cultural, philanthropic and educational institutions in Philadelphia. He was the Medical Director of the Centennial Exposition of 1876, served on the Board of Trustees of the Philadelphia Museums, and was instrumental in founding the Free Library of Philadelphia. Nationally, he pushed for a National University and was a charter member of the American School of Classical Studies in Rome. William Pepper belonged to the American Philosophical Society, the College of Physicians and numerous other organizations. He also found time to contribute to several medical journals, founded the Medical Times, edited the System of Medicind by American Authors, and co-authored Diseases of Children with Dr. John F. Meigs.

William Pepper married Frances Sergeant Perry (great-great-granddaughter of Benjamin Franklin) on June 25, 1873. They had four children, William, born on May 14, 1874; Thomas Sergeant, born on April 14, 1876 and died from diptheria in 1882; Benjamin Franklin, born on January 21, 1879; and Oliver Hazard Perry, born on April 28, 1884. William Pepper died July 25, 1898 from angina pectoris, the same disease that claimed his father's life 34 years earlier.