25th of April Bridge, Lisbon [Post. 6-8-1966] Lisbon, (Portugal) 1 black and white photograph, paper; 23,2 × 16 cm Torre do Tombo National Archives of Portugal PT/TT/SNI/ARQF/DO-014-002B/52478 The city of Lisbon lies on the banks of the vast estuary of the river Tagus. Lisbon occupied the northern (right) side of the river for many centuries, while the sparsely populated south (left) side of the river was used for agriculture and later as an industrial area. Travel between the two sides was very limited, with infrequent boat crossings the only way to traverse the estuary. By the twentieth century, the growth of Lisbon had created a demand for urban development on the south side, which would require the construction of a bridge. Government commissions began analysing the issue during the 1930s, but it would take until the early 1960s before design and construction were entrusted to a consortium headed by the United States Steel Export Company. Construction started in 1962,...