Genealogists, your job is about to get easier.

Today Ancestry.com, a paid-subscription genealogical site, launched the fruits of a three-year project to digitize and index U.S. passenger lists from 1820 to 1960. More than 100 million names will be available in a new database.

Passenger lists are records from vessels docking in U.S. ports. In 1890, U.S. Congress passed a law that all ships arriving at an American port must keep records of the passengers on board. Now the lists provide genealogists with information such as the name, age, and gender of passengers, as well as their occupation, nationality and port of origin.

"It really gives you insight into the sacrifices people made to come to this country," said Mike Ward, senior manager of public relations and promotions at MyFamily.com Inc., parent company of Ancestry.com.

Tim Sullivan, CEO of MyFamily.com, said the records are especially important in a country like the United States, in which many of the citizens have immigrant roots.

"I have great-grandparents that came through these ports, one through Boston and a couple through New York," he said.

He said he hopes the new availability of names and information will get people who before were really not that interested in their genealogy looking into family history.

"We're a nation of immigrants," Sullivan said. "Immigration is a lot in the news these days." He said the release of the online database wasn't timed to coincide with the immigration debate, but it made for an interesting backdrop.

Sullivan said the passenger lists are an important asset to genealogical research because they often provide information such as a person's port of origin that would help link U.S. data with the data from other countries. Ward said before the lists were digitized, people would generally have to scan huge amounts of microfilm images of passenger lists looking for a specific name. Now that the names are indexed and accessible online, a click of a mouse takes searchers to the name they are looking for.

Ward said different lists provide different types of data, with the more current lists generally containing more information than earlier ones. He said one of the important contributions the lists make is simply providing additional information on individuals found through other sources and filling in information gaps. For example, he said, searchers might find children of a family recorded on a passenger list who don't show up in the Census a few years later.

Sullivan said the company decided to digitized the passenger lists based on member feedback.

"It's really in response to the request and desires of our subscription members," he said.

The project required more than 1.8 million hours of labor to complete. The process, according to Ward, involved getting the material to be digitized, photographing it, then allowing handwriting specialists to decipher the information and enter it into the system. He said the company owns software containing one of the largest names dictionaries in the world to help in the process.

Ancestry.com will be offering the complete passenger list data for free on its Web site until the end of November.

The project has been going on for three years now, and bits and pieces of the information have been made available on the company's Web site during the process. However, the majority of the information will be released today.

Sullivan said the passenger list project was one of the most important projects the company has undertaken. The collection will not contain all the passenger lists -- Sullivan said some documents are in such poor condition that they cannot be digitized, but he said the company has done its best to make as many records as possible available. He said that immigration, and therefore passenger lists, are an important part of American history.

The lists not only record immigrants to the country, but show records of travelers, politicians, even Mormon missionaries -- one of Ward's third great-grandfathers appears on a list returning to Utah after a mission. Also, famous personalities of the day and ancestors of some of today's celebrities are recorded in the data: According to a news release, Hillary Clinton's grandfather and his mother appear on an 1881 list as traveling steerage-class to the United States.

Marlow Wootten, a consultant at the Brigham Young University family history library, said the availability of information on the Internet has allowed people to look for information about their ancestors much more quickly and efficiently than they ever could before. He said information that previously would have taken letters, payments and lengthy waits is now available almost at the snap of a finger.

Wootten said there are many reasons people are interested in family history, including very personal ones.

"It gives you a sense of belonging, of who you are," he said.

Ancestry.com is a Provo-based online family history network, which contains a large collection of databases such as U.S. and U.K. census records, U.S. draft cards, etc. A subscription to the site costs $155 per year inside the United States for access to records, or a monthly subscription of $29.95.