The A.C.L.U. tweet, which was sent out Sept. 18, changed Justice Ginsburg’s words, replacing each of her references to women with “person,” “people” or a plural pronoun in brackets. Justice Ginsburg, who died last year, is a revered figure in liberal and feminist circles and directed the A.C.L.U.’s Women’s Rights Project from its founding in 1972 until she became a federal judge in 1980.

The tweet by the A.C.L.U. occasioned mockery and some anger on social media from feminists and others.

“We won’t be altering people’s quotes,” Mr. Romero said in an interview on Monday evening. “It was a mistake among the digital team. Changing quotes is not something we ever did.”