Here's a very readable article from Wikipedia.
(Scroll down to "External Links" for the text of the act.)
Charlotte Ordinance 7056On February 22, 2016, the Charlotte City Council passed, by a 7-4 vote, Ordinance 7056, a non-discrimination ordinance prohibiting discrimination on the basis of sexual orientation or gender identity in public accommodations, passenger vehicle for hire, and city contractors. It was to take effect on April 1, 2016.
North Carolina House Bill 2On March 23, 2016, North Carolina House of Representatives held a special session and passed House Bill 2, with 82 in favor and 26 against and 11 excused absences. About three hours later, the North Carolina Senate also passed the bill, with 32 in favor, 6 excused absences, and all 11 Democrats walking out in protest and not voting. That evening, it was signed by North Carolina Governor Pat McCrory, taking a total of 11 hours and 10 minutes to become a law.
Supporters of House Bill 2 said the Charlotte ordinance was sloppily written and overreaching, and that in their view its wording essentially did away with single-sex bathrooms. Representative Dan Bishop cited this as grounds for the state to override local ordinances.
"One contentious element of the law eliminates anti-discrimination protections for gay, transgender, genderqueer, and intersex people, and legislates that in government buildings, individuals may only use restrooms that correspond to the sex on their birth certificates. This has been criticized because it prevents transgender people who do not or cannot alter their birth certificates from using the restroom consistent with their gender identity: in North Carolina, only people who undergo sex reassignment surgery can change the sex on their birth certificates, and outside jurisdictions have different rules, some more restrictive. The legislation changes the definition of sex in the state's anti-discrimination law to "the physical condition of being male or female, which is stated on a person's birth certificate."
[Perhaps most importantly ]The act also prohibits municipalities in North Carolina from enacting anti-discrimination policies, setting a local minimum wage, regulating child labor, or making certain regulations for city workers. The legislation also removes the statutory and common law private right of action to enforce state anti-discrimination statutes in state courts.">. . .
House Bill 2 does not contain any guidance on how it is supposed to be enforced. It is unclear if bathroom patrons are required to carry birth certificates, or if police departments are obliged to post officers to check them. Police departments in Raleigh, Greensboro, Wilmington, and Asheville have expressed a lack of clarity on how the law should be enforced and an unwillingness to devote police resources to monitor bathrooms. A number of departments indicated a willingness to respond to complaints of violations, but said none had been received.
Republican State Representative Dan Bishop, a co-sponsor of the law, acknowledged that "there are no enforcement provisions or penalties in HB2." Democratic State Representative Rodney Moore was more emphatic, saying: "There is absolutely no way to enforce this law, as it relates to the enforcement of the bathroom provisions. It is an utterly ridiculous law."
North Carolina Attorney General and Democratic gubernatorial candidate Roy Cooper said that House Bill 2 was unconstitutional and that he would not defend it in court, but would defend state agencies against it.
On April 19, 2016, a three-judge panel of the United States Court of Appeals for the Fourth Circuit issued a ruling in favor of transgender high school student Gavin Grimm, upholding the Department of Education's interpretation that Title IX's prohibition on discrimination on the basis of sex should be read broadly to include discrimination on the basis of gender identity (G.G. v. Gloucester County School Board). Although House Bill 2 was not at issue in Grimm's lawsuit, which arose in Virginia, the ruling has controlling status in North Carolina, which is part of the Fourth Circuit. If the Fourth Circuit decision is not overturned via rehearing en banc or on appeal to the Supreme Court of the United States, it would set precedent in the Fourth Circuit that the bill violates Title IX in the educational context."