The USGS said the quake hit at about 4:45 p.m. approximately 6 miles east-northeast of Dover, Delaware and at a depth of about 4.3 miles.
According to the Delaware Geological Survey's website, the most recent data available stated Delaware's strongest quake weighed in at a magnitude 4.1 on October 9, 1971, originating near Wilmington.
It was followed up ten minutes later by a less powerful 5.0 aftershock in the same area, the survey said.
When the tremor took place, it caused a buzz on social media and the Internet in general.
Paul Caruso is a geophysicist with the USGS's natural disaster information center in Colorado. The USGS initially reported the natural disaster as a 4.4, then a 5.1, before dropping back to a 4,4, and now at 4.1 magnitude. However, in DE, the quake jolted downtown Dover, sending lawmakers and workers in the statehouse outdoors to see what happened.
Shock on Social Media Following Delaware Earthquake
Some on Twitter report the quake could be felt in parts of Maryland, West Virginia and Pennsylvania, too. There were no immediate reports of injuries or damage after the jolt rattled the Mid-Atlantic region of the East Coast.
"It felt like I was going up and down and the building was going up and down", he said.
People said they felt shaking for about 10 seconds.
"I turned around and one of my co-workers was coming down the hall with the big-eyes look", he said. "It was actually pretty scary and pretty surprising". She said there were no signs of damage at the base nor would there be any change in its operation.
For some area residents, the event stirred memories of a magnitude 5.8 quake - centered in Louisa County, Virginia - that rocked much of the eastern United States in August 2011.