Dakar's importance increased significantly after 1855, when a railroad linked it with the Senegal River. In 1887 it was made a commune, along with Goree, Rufisque, and Saint-Louis ; the communes together elected a deputy to the French National Assembly. Dakar replaced Saint-Louis as the capital of French West Africa in 1902. In 1923 a new railroad linked Dakar with interior peanut-growing areas and the Niger River. In 1940, Free French forces under Gen. Charles de Gaulle fought unsuccessfully to free Dakar from Vichy control, but in late 1942 U.S. forces occupied the city and stayed to the end of World War II. Dakar was the capital of the short-lived (1959-60) Mali Federation. Since 1945, the city has expanded greatly. Nearby are sandy beaches and a zoological and forest park. Dakar's Roman Catholic cathedral (inaugurated 1929) is the seat of an archbishop. The Univ. of Dakar (1949), the National School of Administration, a school for librarians, and a UN-administered institute of economic development and planning are in the city. It is also the site of the famous Institut fondamental d'Afrique noire, which promotes scholarly research in many fields.

The city hosts many international conferences on artistic and scholarly topics. Dakar's Yoff international airport is the main stopping point for flights from Europe to South America.