Control of the U.S. House and Senate was still up in the air Wednesday morning, as states across the country tallied votes in neck-and-neck midterm election races.A set of close contests will determine whether Democrats keep their slim majorities in the House and Senate, or if Republicans will seize control of one or both chambers of the legislature.

Millions of Americans also cast their votes in key races for governor, secretary of state and other offices down the ballot.