The Q10, which comes with the tiny physical keyboard that many BlackBerry fans admire, is the second device powered by the new BlackBerry 10 operating system.
The touchscreen Z10 launched earlier this year.
The U.S. market is crucial for Waterloo, Ontario-based BlackBerry as it seeks to win back market share ceded to Apple Inc's iPhone, Samsung's Galaxy smartphones and other devices powered by Google's Android operating system.
"This is a very exciting day for us, launching with all four major U.S. carriers," BlackBerry Chief Operating Officer Kristian Tear said in an interview.
Tear said BlackBerry, which has long had a strong base of corporate and government users, expected the Q10 to allow it to win back customers who have been using other devices.
He believed demand for the smartphones would be helped by the fact that a majority of top U.S. companies were testing or installing the BlackBerry Enterprise Service system that would allow them to manage the new devices on their internal networks.
"Since everybody is migrating toward this, we expect it will definitely create pull for our (smartphone) products," he said.
"There are a lot of very loyal BlackBerry keyboard users out there who have been waiting for this and I think, with the Q10, we will also be able to win back prior BlackBerry customers, who are now trying other platforms."
The Q10 launched in Canada, Britain and a few other countries two months ago. The U.S. launch was delayed due to a longer carrier-testing process.
The device is already on sale through T-Mobile in the United States, while rivals Verizon and AT&T have begun to accept pre-orders for shipping later this month. Sprint plans to begin selling the devices this summer.
(Reporting by Euan Rocha; Editing by Janet Guttsman and Bernadette Baum)