In all, more than 400 measures were enacted at the state level during 2012 and will become law in the new year, according to the National Conference of State Legislatures (NCSL).
Some of the statutes, which deal with everything from consumer protection to gun control and healthcare, take effect at the stroke of midnight. Others will not kick in until later in the year.
The raft of measures includes a new abortion restriction in New Hampshire, public-employee pension reform in California and Alabama, same-sex marriage in Maryland, and a requirement that private insurers in Alaska cover autism in kids and young adults, NCSL said.
In New Hampshire, a rarely used form of late-term abortion will become illegal except to save the life of the mother - and even then only if two doctors from separate hospitals certify the procedure is medically necessary.
John Lynch, the state's outgoing Democratic governor, had vetoed the measure, saying it would threaten the lives of women in rural areas. But the state's Republican-controlled legislature later overrode him.
In California and Illinois, laws that take effect at 12:01 a.m. local time will make it illegal for bosses to request social networking passwords or non-public online account information from their employees or job applicants.
Michigan's Republican Governor Rick Snyder signed a similar measure into law earlier this month that took effect immediately. The Michigan law also penalizes educational institutions for dismissing or failing to admit a student who does not provide passwords and other account information used to access private internet and email accounts, including social networks like Facebook and Twitter.
But workers and job seekers in all three states will still need to be careful what they post online Employers may continue to use publicly available social networking information. So inappropriate pictures, tweets and other social media indiscretions can still come back to haunt them.
Gun violence in places where it's all too common, such as Chicago, and in places where it's unexpected, such as Sandy Hook Elementary School in Newtown, Connecticut - was big news in 2012. But only a handful of new state firearms laws are set to take effect in 2013.
In Michigan, the definition of a "pistol" under the law will now include any firearm less than 26 inches in length. The new definition encompasses some rifles with folding stocks and will make the weapons subject to the same restrictions as pistols.
In Illinois, certain guns currently regulated by state law, including paintball guns, will be excluded from the definition of a firearm and participants in military re-enactments will be exempt from some weapons laws.
Another big story in 2012 was the effort by lawmakers in a number of cash-strapped states to put their public employee pension funds on a sounder financial footing.
In California and Alabama, reforms designed to begin to address the unfunded liabilities of those retirement systems will take effect in 2013.
Among the other new laws on the books in 2013
© Thomson Reuters 2012