Gov. Tom Vilsack signed a bill into law Friday declaring English the state's official language.

Though it is mainly symbolic, the law requires all government proceedings be conducted in English. Supporters have said English is a unifying factor in a state that has become increasingly diverse.

Opponents, including many Hispanics and liberals, have called it thinly veiled racism. Most Democrats in the Legislature voted against the bill, which is similar to laws approved in 26 other states.

"I recognize that the bill is not without controversy," Vilsack said. "My hope is that we will look beyond the controversy and put politics behind us so we can focus on our commitments and responsibility to improve education for all our children."

The Legislature sent Vilsack the bill earlier this week after two years of debate.

After the 2000 election, Vilsack launched a campaign to encourage an additional 310,000 immigrant workers to move to Iowa by 2010 to fill employment vacancies and boost dwindling population.

He noted Friday that lawmakers have promised an additional $1 million in a separate bill to fund state efforts helping immigrants learn English.

According to the advocacy group U.S. English Inc., 26 states have some form of official English laws. Similar legislation was approved by the U.S. House in 1996, but the Senate failed to act by the end of the session.