He was born in 1882.
Praeger graduated from Rensselaer Polytechnic Institute in 1915. He served in the U.S. Navy during World War I, after which he spent time at the architectural office of Bertram Goodhue and the New York City engineering firm Madigan-Hyland.
In 1934, as chief engineer for the City of New York Department of Parks & Recreation, Praeger surveyed all New York City parks. Under director Robert Moses, Praeger created architectural drawings, descriptions, and photographs for every park that the city owned. He also acted as head of the civil engineering department at RPI from 1939-1946.
During World War II, Praeger served in the US Navy, and he eventually reached the rank of captain. He developed the original design of the concrete floating breakwater - known as "Phoenix" - for the Invasion of Normandy.
He died on October 16, 1973.
- Henry Hudson Bridge, (chief engineer) New York, 1932
- Marine Parkway-Gil Hodges Memorial Bridge, (chief engineer) New York, 1937
- Pier 57, New York City, 1952
- Arecibo Radio Telescope in the Arecibo Observatory, Puerto Rico, 1952.
- Holman Stadium, (chief engineer) Vero Beach, Florida, 1953
- Tappan Zee Bridge, New York, 1955
- Throg's Neck Bridge, (consulting engineer) New York, 1961
- Shea Stadium, Flushing, New York, 1964
- Dodger Stadium, Los Angeles, California, 1962
- "Emil H. Praeger". RPI Alumni Hall of Fame. Retrieved 7 August 2011.
- Wolf, Donald E. (2010). Crossing the Hudson: Historic Bridges and Tunnels of the River. Rutgers University Press. p. 180. ISBN 9780813547084.
- "Green Spaces and Moody Places". The Brooklyn Historical Society Blog RSS [Brooklyn Historical Society Blog. Retrieved 7 August 2011.
- "Walter O'Mally History". Retrieved 7 August 2011.