Charles Findeisen (1919-2007) was an aerial photographer hobbyist turned professional and spent most of his life flying airplanes. Findeisen consulted for real estate development concerns, engineering firms, and construction companies among others. Virtually all of his work was in the tri-state region of New Jersey, Pennsylvania, and Delaware.

This collection contains his aerial photography from 1962 to 2000. It is comprised mostly of negatives but does include some photographs. Many of his subjects were photographed over time at regular intervals. This is particularly true of real estate development programs and building projects. But there is also one-off material of current events, local places, and landmarks.

The Dallin Aerial Surveys Company produced aerial photographs for newspapers, businesses, municipalities, and private individuals. The company was founded in 1924 by Colonel J. (John) Victor Dallin (1897-1991), a Royal Flying Corps-trained pilot who served in World War One. During WWI he became involved in aerial photography on a reconnaissance mission during the latter stages of the war. This collection consists of over 13,000 aerial photographs primarily of the Mid-Atlantic region taken between 1925 and 1941. The company made vertical and oblique aerial photographs of factories, private estates, schools, country clubs, towns, airports, rivers, and many other sites and some news events of the day. The subject with the largest number of views is the city of Philadelphia.

The collection consists of 46 nitrate negatives and one folio filled with 46 vertical aerial photographs of New Castle County, Delaware and the surrounding areas, including nearby southern Chester County, Pennsylvania. The flight altitude was approximately 25,000 feet and the resulting vertical photographs had a scale of approximately 1 inch to 3,100 feet.

Earth Resources Technology Satellite (ERTS), now known as Landsat 1, was the first satellite launched as part of the Landsat program to continuously record observations of Earth from space. ERTS was launched on July 23, 1972. This small collection consists of eleven transparencies showing satellite images of locations in the southwestern United States and Rocky Mountains taken by NASA's Earth Resources Technology Satellite on February 2, 1975.

Northern Delaware (current day New Castle County) was settled by Swedes in the seventeenth century. This collections contains ten aerial photographs of the Northeastern Delaware border with Pennsylvania, along the Delaware River.