If you are spending up to 3 weeks in the USA T-mobile has a pretty decent tourist sim card plan:
https://prepaid-phones.t-mobile.com/...l-tourist-plan
$30 USD gets you 2GB of LTE speed with unlimited lower speed data, unlimited USA and international texting and 1000 minutes of USA talk time AND the SIM card.
Only drawback is the plan expires after 3 weeks and no renewals.
There are so many cheap pay as you go plans in the US as well that if you have the time to visit a store you can get a sim card for too.