Nearly a foot of snow has accumulated in parts of Illinois, Indiana, Kansas, Maine, Massachusetts, Missouri, New Hampshire, New York, Ohio, Pennsylvania and Vermont -- and more than a foot was possible from northeastern Pennsylvania to southern New Hampshire, AccuWeather.com reported.
Power outages were reported in several states, including Arkansas, West Virginia, Pennsylvania, Maryland, Tennessee and New Jersey.
In Maryland, icy rain glazed the Baltimore area, slicking roads and knocking out power for nearly 120,000 customers statewide, the Baltimore Sun reported. Schools across the state either canceled classes or operated on delayed basis.
More than a foot of snow fell in Topeka, Kan., while nearly 9 inches fell in Wichita Tuesday before the system began its push east, Weather.com reported.
Officials in Kansas said snowy conditions led to a car crash in which two people died in Crawford County.
In Arkansas, ice bent trees, snapped power lines and left thousands of customers without power, CNN said. Portions of Interstate-55 near Jericho and Marion were "nearly impassable," officials said. A man died in a single-vehicle crash when he lost control on an icy bridge and slammed into trees, police said.
The snow was expected to taper off Wednesday afternoon in the New England states, forecasters said, but not before the region was blanketed with as much as a foot of fresh snow. Roads and highways were closed due to the weather and accidents, and mass transit was curtailed in many areas.
In Pennsylvania, officials reported a tractor-trailer accident on the Pennsylvania Turnpike near Harrisburg killed one person Wednesday.
Slick roads were also suspected in a fatal two-vehicle crash in Des Moines, Iowa, police said.
Blowing snow was a possible factor in a collision between a farm tractor and a pickup truck in Nebraska in which one person died, police said.
Government offices and schools were closed or operating on a delayed basis in many states.
The governors of at least three states -- Mississippi, Kansas and New Jersey -- declared states of emergency to deal with storm response.
On the New Jersey emergency management office's Twitter feed, meteorologist Gary Szatowski said the National Weather Service's "reasonable worst case scenario" for parts of New Jersey and other states called for 0.75 inches of ice accumulation that could result in as much as five days without power.
Ice build-up on trees and power lines disrupted service to more than 400,000 customers in the Philadelphia area, AccuWeather.com reported.
Winter weather warnings were posted from central Kansas to southern Maine. CNN estimated about 120 million people were in the storm system's path.
FlightAware.com reported 2,765 flights had been canceled and 3,815 flights were delayed at U.S. airports by mid-afternoon Wednesday. Liberty International Airport in Newark, N.J., reported 53 percent of its flights were either delayed or canceled mid-morning Wednesday.
Two Delta Air Lines jets got stuck in snow in separate incidents at Detroit Metro Airport, CNN reported.
A Southwest Airlines plane got stuck in the snow as it taxied on a runway at Kansas City International Airport Tuesday afternoon, KMBC-TV, Kansas City, reported. Passengers deplaned and were bused to the terminal.
Texas Gov. Rick Perry renewed a waiver making it easier for trucks to haul propane through the Lone Star state to others regions that have declared a propane emergency.