"DeVos shows an antipathy for public schools; a full-throttled embrace of private, for-profit alternatives; and a lack of basic understanding of what children need to succeed in school," Weingarten stated on Tuesday. "That makes this a sad day for children."
Earlier on Tuesday, the US Senate confirmed DeVos as secretary of the US Department of Education with Vice President Mike Pence casting the tie-breaking vote for a final tally of 51-50.
Teachers unions were among the most vocal opponents of DeVos, a longtime school choice activist who backs government issued vouchers that allow children in poor neighborhoods to attend private schools.
Teachers unions, with strong support among Democratic lawmakers, campaigned throughout the administration of former president Barck Obama to restrict alternative approaches to educate children who are forced to attend poorly performing public schools.