US president-elect Donald Trump offered a Thanksgiving prayer for unity after “a long and bruising” campaign season as his cabinet began to take shape.

“Emotions are raw and tensions just don’t heal overnight,” the incoming president said in a video message released on the eve of the national holiday. He continued: “It’s my prayer that, on this Thanksgiving, we begin to heal our divisions and move forward as one country strengthened by shared purpose and very, very common resolve.”

Trump, who was gathered with his family at his Palm Beach estate on Thursday, was expected to pause for a day after a two-week scramble to shape his administration from scratch. He injected the first signs of diversity into his cabinet-to-be on Wednesday, tapping South Carolina Governor Nikki Haley to serve as US ambassador to the United Nations and charter school advocate Betsy DeVos to lead the Department of Education.

They are the first women selected for top-level administration posts.

Haley is the daughter of Indian immigrants, so she was also his first minority selection after a string of announcements of white men. She has little foreign policy experience, yet Trump praised her as “a proven deal-maker”. DeVos, like Trump, is new to government but has spent decades working to change America’s system of public education.

Retired neurosurgeon Ben Carson said on Wednesday that “an announcement is forthcoming” on his role, which would make him the first black choice – possibly as secretary of Housing and Urban Development – but he also suggested he would be thinking about it over the Thanksgiving holiday.

“I feel that I can make a significant contribution, particularly to making our inner cities great for everyone,” he wrote on his Facebook page.

Trump is also expected to select billionaire investor Wilbur Ross Jr to lead the Commerce Department, a senior Trump adviser said on Wednesday.

The 78-year-old is chairman and chief strategy officer of private-equity firm WL Ross & Co, which has specialised in buying failing companies.

Wednesday’s appointments came as Trump worked to distance himself from the “alt-right”, a movement of white supremacists who continue to cheer his election. His first appointments included chief counsellor Steve Bannon, who previously led a website popular among the alt-right.

“It’s time to restore the bonds of trust between citizens, because when America is unified there is nothing beyond our reach,” the president-elect said in his Thanksgiving message, which was posted on social media.

The nasty campaign season included clashes between Trump and his new cabinet selections.

“The people of South Carolina are embarrassed by Nikki Haley!” Trump wrote in March. Haley denounced several of his campaign comments and urged voters to “reject the siren call of the angriest voices”. DeVos, who is from Michigan, told the Associated Press in July: “A lot of the things he has said are very off-putting and concerning.”

On Wednesday, however, Trump and his colleagues had nothing but kind words for each other.

And while other Republicans largely praised the choice of Haley, DeVos faced immediate criticism from left and right.

The president of the National Education Association, Lily Eskelsen Garcia, said in a statement that for years DeVos “has lobbied for failed schemes, like vouchers, which take away funding and local control from our public schools to fund private schools at taxpayers’ expense”.

At the same time, some conservatives warned that the long-time Republican donor also supports the Common Core education standards that Trump railed against during the campaign.

DeVos addressed the criticism head-on, posting a “Q&A” statement that said of Common Core: “I am not a supporter – period.”