By Michael Martinez
(CNN) -- For professional genealogists -- and amateurs like actor Edward James Olmos -- an extraordinary moment is unfolding for the nation's Latino community, thanks to the digital age.
It's the revelation of the 1930 Mexican census, which was distributed free online this year.
Decades ago, such data might not have been as meaningful. But the United States' own recent census now shows that Latinos are the nation's No. 2 group in 2010. With 50.5 million Hispanics now in the United States, the 1930 Mexican census offers a glimpse into the heritage and history of an emerging cornerstone community -- especially because 31.8 million Americans are of Mexican descent.
"All of the information that we're getting from the census is really extraordinary because it's leading us into different realms of understanding of what was happening at the time to our family," Olmos said. "It's been quite an experience to go in there, and it's been very educational."
The 1930 Mexican census -- with its handwritten entries on large sheets of rowed and columned paper -- is now an online database accessible for free at ancestry.com/mexico.
The online materials show nearly 13 million census documents, which offers information such as head of household; age; civil or church marriages or living together in "free union"; ability to read and write; occupation; place of birth; language spoken, including any indigenous languages; physical or mental defects; and religion.
The 1930 Mexican census is regarded as the earliest, most thorough accounting of that country's population. It counted 90% of the people living there, although the residents of Mexico City aren't included because of records are missing, said George Ryskamp, associate professor of history at Brigham Young University, who has researched, taught and lectured on genealogy in Latin America and Spain.
"It's extremely significant," Ryskamp said of the 1930 Mexican census. "I [have been] doing Spain and Latin American genealogy for the past 35 years. When I first started out, there wasn't a lot of interest.
"It's just exciting to see that we've reached a point, at least commercially, that there are enough people of Mexican ancestry [in the United States] that they are putting up that information. Genealogically, it represents a significant step. It recognizes that this is a minority group whose needs have been recognized and are going to be met."
Later Mexican census records aren't available yet or are believed missing, Ryskamp said.
David Hayes-Bautista, professor of medicine and director of Center for the Study of Latino Health and Culture at the University of California at Los Angeles, said the 1930 documents are "an important marker census."
"During the revolution, Mexico actually lost population: About a million people died and about a million people left [for the United States]," Hayes-Bautista said. "And that was when Mexico was run by an 80% rural population. This captures Mexico just as it starts to shifts to an urbanized population."
That mass migration during the revolution included Olmos' maternal grandmother and her family, who "were some of the intellectuals who really forged the Mexican Revolution in 1910," Olmos said.
"They had to escape out of Mexico" because of it, he said.
But when they continued advocating the revolution from the U.S. side of the border, the U.S. government threw his forebears in jail, the Oscar-nominated actor said.
"They were really feeding the war in Mexico from St. Louis and from Los Angeles, and they were then put into prison in Leavenworth, Kansas," Olmos said. "One of my great uncles was killed there."
Olmos said the information can be enriching to Latinos, including U.S.-born Mexican-Americans who might want to seek dual citizenship with Mexico and need to prove a parent was born in Mexico. Olmos is a paid spokesman for Ancestry.com.
Olmos secured dual citizenship after he spent eight years searching for his father's birth records. In the end, he never found the birth certificate, but he did find "a birth memoir inside a hospital" that noted his father's birth in Mexico City in 1922, Olmos said. His mother was born in Los Angeles, he said.
"Many of us should take into consideration that, if your parents were born in Mexico, then you can become a Mexican citizen and that gives you opportunities to vote," Olmos said.
"It gives you the opportunities to comment, and it gives you the opportunity to help when it's most needed right now in Mexico, which is the turmoil that's going on there. This opens up the door for you to realize how deeply you are rooted in Mexico and how what happens in Mexico has a direct issue and foundation on who you are as a human being, and you can help."
"I think that's what we all should be doing is trying to help - where we come from," Olmos said. "If you're Irish, I'm sure you should think about the Irish people. And if you're English, or if you're African, or if you're German, or if you're Dutch, you'll be definitely thinking about your root, and the deeper you go into that, the more you understand why you should be a part of understanding and helping those regions of the world."