many irish people have left ireland and moved to the united states, canada, australia, and south america. the great famine (1845 to 1849 inclusive) forced many to leave; it is estimated almost a million people died of starvation, and a million more emigrated. from a maximum of over 8 million in 1841, the total irish population dropped to just over 4 million in the 1940s. since then, the population has grown to over 6 million. this has been helped by the economic growth of the "celtic tiger" and since 2004 immigration from countries in eastern europe such as poland.