History: Wild West By Timothy H. O'Sullivan

In 1864, following Gen. Ulysses S. Grant's trail, he photographed the Siege of Petersburg before briefly heading to North Carolina to document the siege of Fort Fisher. That brought him to the Appomattox Court House, the site of Robert E. Lee's surrender in April 1865.
From 1867 to 1869, he was official photographer on the United States Geological Exploration of the Fortieth Parallel under Clarence King. The expedition began at Virginia City, Nevada, where he photographed the mines, and worked eastward. His job was to photograph the West to attract settlers. O'Sullivan's pictures were among the first to record the prehistoric ruins, Navajo weavers, and pueblo villages of the Southwest. In contrast to the Asian and Eastern landscape fronts, the subject matter he focused on was a new concept. It involved taking pictures of nature as an untamed, pre-industrialized land without the use of landscape painting conventions. O'Sullivan combined science and art, making exact records of extraordinary beauty.
In 1870 he joined a survey team in Panama to survey for a canal across the isthmus. From 1871 to 1874 he returned to the southwestern United States to join Lt. George M. Wheeler's survey west of the 100th meridian west. He faced starvation on the Colorado River when some of the expedition's boats capsized; few of the 300 negatives he took survived the trip back East. He spent the last years of his short life in Washington, D.C., as official photographer for the U.S. Geological Survey and the Treasury Department.
O'Sullivan died in Staten Island of tuberculosis at age 42.