Historical note

The Packer Collegiate Institute was established as the Brooklyn Female Academy on Joralemon Street in the Brooklyn Heights neighborhood of Brooklyn in 1845. It was formed by a committee of local citizens who were interested in the education of young women. The school's first president was Dr. Alonzo Crittenden, who presided over a student body of 350 girls from 19 states.

The school burned down on New Years' Day, 1853, and reopened in 1854 with the assistance of a generous $65,000 gift—the largest donation to aid American secondary education at the time—from Mrs. Harriet Packer, widow of William Packer, and former trustee of the Brooklyn Female Academy. One condition of Packer's donation was her request for the dissolution of the Brooklyn Female Academy Corporation, which was to be replaced by what is today's Packer Collegiate Institute. Prominent Brooklyn architect Minard LaFever designed the Gothic Revival building, presently known as Founders Hall.

In 1883, after Crittenden's death, Truman Backus assumed the role of Packer's new president. As a result, religious studies ceased to be part of the curriculum. During this period, Packer rose to a position of national preeminence in female education. In 1887, the east wing, designed by Napoleon Le Brun, was built to house the gymnasium and science laboratories. In 1907, an Alumnae Hall was adjoined to the physical plant and the subway was constructed under Joralemon Street, which required the school to remove the observatory dome from the main building. Spanning the years 1908 to 1918, Edward Jasper Goodwin served as president and the students received letter grades for the first time.

John Denbigh succeeded Goodwin and served as president until 1938, overseeing the 1926 addition of the penthouse in Alumnae Hall. Denbigh presided over the establishment of Packer's Junior College in 1919. The school endured the financial impacts of the Great Depression, which resulted in teacher layoffs and salary cuts. In 1938 Paul Shafer became the fifth president of Packer and oversaw the Centennial celebration in 1945. During the 1950s, Packer's Junior College began awarding Associate Degrees and in 1957, Pratt Hall was added to Packer's growing complex of buildings. In 1968, President Shafer retired and Jack Skillman took over the post. In 1969, the school acquired nearby St. Ann's Church.

By 1972, the Institute experienced major changes, including the disbandment of the Junior College and the introduction of a co-ed student body. The elementary school was divided into Lower and Middle schools during this decade and Peter Esty became headmaster in 1982. Succeeding Esty was J. Geoffrey Pierson who served as the president of Packer from 1990 through 2004. Pierson oversaw the major renovation of the school's buildings and grounds, include the complete renovation of the St. Ann's Church building, which was was completed in 2003. Following Pierson's retirement, Bruce Dennis became the head of school in 2004.