With some races still undecided, Democrats were headed for a gain of more than 30 seats, beyond the 23 they needed to claim their first majority in the 435-member House in eight years.
The results of Tuesday's vote mean that the Republicans no longer hold both wings of the US Congress, handing Mr Trump’s political opponents a stronger foothold in Washington from which to oppose his presidency.
The elections have already made history, with a record number of women, Native Americans, and Muslim candidates running for office.
Rashida Tlaib and Ilhan Omar won in their Democrat-safe seats becoming the first Muslim congresswomen, while Alexandria Ocasio-Cortez made history as the youngest woman to join Congress.
Anna Eskamani was elected to Florida House District 47 Tuesday, becoming first elected Iranian-American to hold any elected office in the Sunshine state.
The Democrats now have the numbers to veto Mr Trump’s proposed laws in the House and launch a string of damaging investigations into his administration through the committees they will control.
LR/PR