Officials said several agencies responded to the incident.
The National Hurricane Center said Florence came ashore near the town of Wrightsville Beach, almost 10 kilometers east of the city of Wilmington, and is now inland near Cape Fear packing sustained winds of 130 kilometers per hour with higher gusts.
Donald Trump was to visit hurricane-hit zones "early to the middle of next week", the White House said, "once it is determined his travel will not disrupt any rescue or recovery efforts".
The NHC described Florence as a "slow mover" and said it had the potential to dump historic amounts of rain on North and SC, as much as one metre in some places.
At least 150 people were waiting to be rescued in New Bern, N.C., officials tweeted Thursday evening.
Florence was moving west-southwest at about 5 miles per hour (7 km/h), with its center located over eastern SC. "You may need to move up to the second story, or to your attic, but WE ARE COMING TO GET YOU".
Once Hurricane Florence is over, researchers can begin compiling data on how much rain fell, and other factors, to present a more robust paper, Reed said.
But forecasters say Florence's biggest threat, as with all hurricanes, lies in its water: a storm surge of up to 11 feet and rainfall that will trigger catastrophic flooding. The storm is expected to turn west and then north moving through the Carolinas and the Ohio Valley by Monday, the NHC said early on Saturday.
As Hurricane Florence passes through Hampton Roads, many are wondering what to do with the extra perishable supplies they accumulated in preparation for the storm.
Just a few minutes before the now-Category 1 storm made landfall, cameras on board the International Space Station managed to catch the mesmerising footage below.
About 10 million people could be affected by the storm and more than one million were ordered to evacuate the coasts of the Carolinas and Virginia.
"WPD can confirm the first two fatalities of Hurricane #Florence in Wilmington".
"The fact is this storm is deadly and we know we are days away from an ending", Cooper said.
Hurricane-force winds extended 80 miles from its center, and tropical-storm-force winds up to 195 miles.
Officials said some 1.7 million people in the Carolinas and Virginia were warned to evacuate, but it's unclear how many did.
"I'm a bit skeptical about detection and attribution of specific weather events", said Michael Mann, director of the Penn State Earth System Science Center.