"It tells about the human relations that existed in California before the Spanish arrived," Hackel said. "It's not every bit of information, but it provides great insights."

For researchers, there has never been a single source of relevant information on the life of the mission residents. "The database itself has a completeness that is very unusual," Hackel said.

One important use for the information, he said, is that it can be used to help researchers better glean details about California during colonial times. One problem with U.S. history books, he said, is that they often tell only about the original 13 colonies on the East Coast, giving short shrift to history and activities in California and the West.

"We think this is part of a monumental effort to move toward a more continental vision of U.S. history, not just the Eastern Seaboard," he said.

Robert Ritchie, director of research at the Huntington Institute, said the database is already providing help to people who have been perusing and querying it online since it went live. "You can glean an awful lot of information about how people survived," he said. "You can see how families survived and interacted with local native peoples."