Four overseas immigration movements have taken place in recent decades: approximately 5,000 refugees from the Spanish Civil War in the late 1930s; a Jewish refugee group, which arrived in 1940; a continuous flow of Japanese, mainly farmers, since 1950; and 600 Hungarian refugees invited by the government in 1957. These are dwarfed, however, by the influx of Haitians, some seasonal, others permanent. The number of Haitians living in the Dominican Republic has been estimated at 500,000 to 1,000,000.
Emigration became significant for the first time during the 1960s, when 93,300 Dominicans legally entered the US; during 1971–80, the figure rose to 148,100, and during 1981–85, it was 104,800. In 1990 there were 357,000 Dominican-born people living in the US, mostly along the eastern seaboard. This census total may have been an undercount, for estimates of the Dominican population in the US ranged as high as 1,000,000, including 200,000 in Puerto Rico.
An estimated 35,000 Haitians entered the Dominican Republic after the military coup that overthrew Haiti's president, Jean-Bertrand Aristide, in September 1991. By May 1997, 20,000 Haitians had returned to their homeland, voluntarily or by deportation. The majority of Haitian refugees live outside the capitol, Santo Domingo. The Dominican Republic government initiated a program to deport illegal migrants back to Haiti. However, this program does not affect recognized refugees or asylum seekers, as they receive temporary residence permits. The net migration rate in 2000 was -1.4 migrants per 1,000 population, down from -3.3 migrants per 1,000 population in 1990. The total number of migrants living in the Dominican Republic in 2000 was 136,000.