Edit: Now that we're talking about it, look. There is all the countries ratification dates, along with considerations for their laws.

And you can check the convention here.

Edit 2: For those in the US who want to check their state's laws compliance to the convention, there is this site.

Edit 3: The map source btw. Its from wikipedia.

The main violations:

Marriage below 18 years of age. No minimum age for marriage in 6 States, 15 years old in 2 States, 16 years old in 24 States and 17 years old in 9 States. CRC compliance in 0 states.

Corporal punishment. Legal in private schools in 25 states and legal in public or private schools in 22 other states, legal in the home in 50 states, legal in juvenile detention in 6 states. CRC compliance in 0 states.

Child labor below 15 years of age. Varies per sector. The biggest issue in the US is exemptions for work by children in agriculture: No minimum age in 23 states, 9 years old in 1 state, 10 years old in 2 states, 12 years old in 11 states, 12 years old in 1 state, 14 years old in 12 states. CRC compliance in 0 states.

Juvenile Jurisdiction and imprisonment. No minimum age in 24 states, 7 years old in 2 states, 8 years old in 1 state, 10 years old in 15 states, 11 years old in 1 state, 12 years old in 5 states, 13 years old in 2 states. CRC compliance in 0 states. Trying children as adults: No minimum age in 22 states. 12 years in 4 states, 13 years in 4 states, 14 years in 16 states, 15 years in 2 states, 16 years in 1 state. CRC compliance in 0 states. Juveniles can be sentences to life without parole in 22 states. Children as young as 13 years old have been sentenced to life in prison without parole.