Detroit ? The American Civil Liberties Union on Friday dropped a lawsuit challenging the constitutionality of the USA Patriot Act.

The ACLU said it was withdrawing the lawsuit, which it filed more than three years ago, because of “improvements to the law.” The Justice Department argued last month that amendments approved by Congress in March 2006 had corrected any constitutional flaws in the Patriot Act.

The lawsuit, filed in July 2003 on behalf of the Muslim Community Assn. of Ann Arbor and five other nonprofit groups, was the first legal challenge to Section 215, the part of the Patriot Act that lets federal agents obtain such things as library records and medical information.

The ACLU said the revisions allow people receiving requests for records to consult with a lawyer and challenge the requests in court.