In 1881, an 11-year-old boy in China named Yung Wah Gok begged for a chance to go to the United States like the thousands of other Chinese workers who had already left to seek their fortune on the railroad, in laundries and working other jobs.

A year later, immigration laws swung the door shut by barring Chinese laborers from entering the United States or naturalizing as citizens if they already were here. If Wah Gok had not persuaded his uncle to take him, he might never have emigrated.

This first attempt at regulating immigration to the United States tore apart families, cut the Chinese population in the United States in half, and forced many Chinese Americans to perpetuate secrets and even lies well into the 20th century.

"It created total exclusion from American life," said Wah Gok's granddaughter Connie Young Yu, 65, a Bay Area native. "If they could never be citizens, how could they participate?"

Today is the 125th anniversary of the signing of the 1882 Chinese Exclusion Act, and the Chinese Historical Society of America in San Francisco is hosting commemorative events all month.

Growing up, Young Yu heard many stories about how the act affected her family. To find a wife, her grandfather had to return to China because of laws that prevented him from marrying here. And he waited 14 years to bring his wife home; he had to prove he had become a merchant, a loophole that admitted very few.