Retirees and other residents from all over the country were among those who donated nearly $500,000 to help Arizona defend its immigration enforcement law, with most chipping in $100 or less, according to an analysis of documents obtained Thursday by The Associated Press.

The donations, 88 percent of which came through the Arizona defense fund's website, surged this week after the federal government sued Tuesday to challenge the law. A document from Gov. Jan Brewer's office showed that 7,008 of the 9,057 online contributions submitted by Thursday morning were made in the days following the government's filing.

Website contributions came from all 50 states, plus the District of Columbia and Puerto Rico, including nearly 2,000 from Arizona. Donations ranged from $5 to $2,000, with the vast majority between $10 and $100.

The AP examined about a quarter of the fund's total contributions, and found only two that came from businesses.

The willingness of thousands of individual Americans to contribute to the Arizona fund illustrates broad concern and frustration over border security and illegal immigration. The state's legislation has since renewed calls for broader immigration changes.

The Arizona law includes a requirement that police enforcing another law generally must investigate the immigration status of people if there is "reasonable suspicion" to believe the people are in the United States illegally.