1. The Washington Monument in 1869.

2. The New York Times building under construction in 1903.

3. The construction of the Manhattan Bridge in 1909.

4. The Lincoln Memorial in 1916.

5 The construction of the Brooklyn Bridge, 1883.

6. The LA City Hall under construction in 1927.

7. The Chrysler Building under construction, circa 1929.

8. The construction of the Empire State Building in the early 1930s.

9. A man stands on cables over the Golden Gate Bridge, circa 1933.

10. The construction of the LAX Theme Building, circa 1960.

11. The World Trade Center, circa 1966.

12. Ceasar's Palace construction, in Las Vegas, circa 1965.

13. San Francisco's Transamerica Building, circa 1969.

14. The Sears Tower under construction in 1970.

15. Epcot under construction in the early 1980s.

During the incredible building boom of early 20th century many of iconic buildings we all know well were being under construction. It may be hard to imagine that iconic landmarks like the Golden Gate Bridge or the Empire State Building ever didn’t exist.