24hCasino is regulated by Malta and powered by Netent casino games. Both Malta and Netent do not accept citizens from the United States of America.
I sent an email to the 24hCasino support to get a clear explanation. Here is their answer :
Thank you for contacting us.
Unfortunately we do not accept players from United States. Please specify from which country you want to play and where do you live.
Should you have any other questions, then please feel free to contact us.
As part of the US gambling law, 24hCasino preferred to step back from the US Markets. However, some online casinos still continue to accept US citizens. Check our top 3 US Casinos.
Technically, you could play to 24hCasino if you signed up from abroad. For instance if you are in vacation in Cancun or in Panama, you could play to 24hCasino while you drink your Tom Collins. However, you should not use a US address and an american credit card (from RBS for instance).
This is the same problem as "signing-up from abroad". You could use a VPN to play to 24hCasino, but you would need to have a real address outside of the US (with phone bill at your name for instance). If you have your father abroad, for instance in the South Africa, it could work. Otherwise, in case you win a $5,000,000 jackpot, 24hCasino could block your funds..
We know that Bovada is currently accepting US citizens. It is powered by Top Game software and offers a nice welcome bonus.