Each year a list of Free fishing days are published, find that list HERE
Here are a few examples:
Pennsylvania free fishing days: May 28, 2012 (Memorial Day) & September 3, 2012 (Labor Day)Fish-for-Free Days allow anyone (resident or non-resident) to legally fish with NO FISHING LICENSE REQUIRED to fish on all Pennsylvania's waterways on the designated days. All other fishing regulations still apply. Two dates are typically chosen.
Each year, the last full weekend in June is designated as Free Fishing Days in New York State. During those two days, anyone can fish New York State waters, and no fishing license is required. This event started in 1991 to allow all people the opportunity to sample the incredible fishing New York State has to offer. Since no license is required, it is the perfect time to take a friend or relative fishing. In 2012, New York State's Free Fishing Days are Saturday and Sunday, June 23 & 24.
Saturday and Sunday, June 16 and 17, will be New Jersey's Free Fishing Days in 2012. Free Fishing Days are held annually in conjunction with National Fishing and Boating Week, and on these days anyone may fish the Garden State’s public waters without a license or trout stamp. All other regulations, including size and daily catch limits, remain in effect. Anglers should also note that any smallmouth or largemouth bass caught during this time must be released.