New Jersey's first white settlers were inter-colonial migrants: Dutch from New Amsterdam, Swedes from west of the Delaware River, and Puritans from New England and Long Island. By 1776, New Jersey's population was about 138,000, of whom perhaps 7% were black slaves.
Population growth lagged during the early 19th century, as discouraged farmers left their worn-out plots for more fertile western soil; farmers in Salem County, for example, went off to found new Salems in Ohio, Indiana, Iowa, and Oregon. Not until the rapid industrial growth of the mid-1800s did New Jersey attract great waves of immigrants. Germans and Irish were the first to arrive, the latter comprising 37% of Jersey City's population by 1870. The late 1800s and early 1900s brought newcomers from Eastern Europe, including many Jews, and a much larger number of Italians to the cities. By 1900, 43% of all Hudson County residents were foreign-born. More recently, migration from Puerto Rico and Cuba has been substantial. In 1990, 143,974 New Jersey residents age five and older had lived in Puerto Rico in 1985. In 1996, 1,152,000 New Jersey residents, or 14%, were foreign born. In 1998, 35,091 foreign immigrants entered the state, the 5th-highest total for any state that year.
From World War I on, there has been a steady migration of blacks from southern states; Newark's black population grew by 130,000 between 1950 and 1970. Black as well as Hispanic newcomers settled in major cities just as whites were departing for the suburbs. New Jersey's suburbs were also attractive to residents of New York City, Philadelphia, and other adjacent areas, who began a massive move to the state just after World War II; nearly all of these suburbanites were white. From 1940 to 1970, New Jersey gained a net total of 1,360,000 residents. Between 1970 and 1990, however, the state lost about 250,000 residents through migration. Between 1990 and 1998, New Jersey had a net loss of 350,000 in domestic migration and a net gain of 360,000 in international migration. While the black, Hispanic, and Asian populations were still rising, whites were departing from New Jersey in increasing numbers. As of 1998, New Jersey's black population numbered 1,188,000; Hispanic, 866,000; and Asian, 453,000. Between 1990 and 1998, the state's overall population increased 4.7%. In the period 1995–2000, 534,578 people moved into the state and 717,407 moved out, for a net loss of 182,829. About 118,905 people moved to Florida.