After putting the United States 2-1 up in the 31st minute, Morgan ran to the sideline and stopped to sip an imaginary cup of tea, sparking a slew of memes and American Revolution references on social media.
The victory came two days before Independence Day in the United States, which commemorates the Declaration of Independence from Britain by 13 American colonies in 1776.
Morgan came in for some criticism for the celebration, with England international Lianne Sanderson describing it as "distasteful".
"I think tonight I expected Alex to grab a goal, but I'm not that happy with that celebration," the Juventus forward told beIN Sports.
"I could be wrong but it's based upon playing against England and we love our tea in England. I'm not a tea drinker but that's what we're connected with so I think it's a little bit distasteful."
Morgan said the celebration was her way of responding to the U.S. team critics, who have accused the defending champions of arrogance.
"I wanted to keep it interesting," she said. "I know Megan Rapinoe has the best celebration. I had to try and step up this game.
"I feel like this team has had so much thrown at them and us. I feel like we didn't take an easy route through this tournament and 'that's the tea.'"
(Reporting by Hardik Vyas in Bengaluru; Editing by Peter Rutherford)