Perhaps you refer to the California Gold rush of 1849 or the Alaska 'Gold Rush' of jobs in 1949, but there appears to be no historical Gold Rush in 1949 anywhere in the world.
The 1849 Gold Rush brought many new settlers to California and swelled San Francisco from a sleepy 800 population to nearly 12000. The definition is an inrush of people seeking jobs and riches due to the discovery of gold at Juhn Sutter's mill.
The importance? Well California was a US insular territory, and within a year it had a constitution (approved by a vote of roughly 12.000 to 800 opposed) and an elected governor (all without the approval of congress) and in 1850, the U.S. Congress did approve the independent actions of California and granted statehood.
Even today California, if it were an independent nation, would have the sixth largest GNP, and Californians still have a reputation for independence and perhaps a little craziness.
