Pennsylvania was among six states that had yet to be called including Alaska, Arizona, Georgia, North Carolina and Nevada.
Expect more fireworks as Trump's personal lawyer, former New York City Mayor Rudy Giuliani, has joined the election fray.
Giuliani tweeted: "En route to Philadelphia with legal team. Massive cheating. @realDonaldTrump up by 550,000 with 75% counted. Will not let Philly Democrat hacks steal it!"
Biden and Trump both declared victory in Pennsylvania, as reported here by The New York Post.
While vote-counting was taking longer than usual in Pennsylvania, Gov. Tom Wolf said it's a sign that the process is working.
Trump also is demanding a recount in Wisconsin, where Biden won. The president's campaign manager Bill Stepien said there were irregularities in several Wisconsin counties, the AP reports.
The Keystone State had nearly 3 million mail-in ballots, with approximately 400,000 mail-in ballots that awaited counting as of Wednesday afternoon, USA Today reports. Those votes were overwhelmingly in favor of Biden, which could tip the race in his favor, the outlet said.
USA Today says that's because more Republicans voted in-person due to months of Trump criticizing mail-in ballots, while many Democrats voted by mail, USA Today says.
Election officials said ballot counting could extend into Thursday in Pennsylvania, NBC reports.
Philadelphia officials created a live stream of their ballot-counting process on YouTube. You can watch that by clicking here.
Click here to follow Daily Voice Cresskill-Closter and receive free news updates.