Masterton Mayor Garry Daniell took the time to explain the historic photographs in the lounge, before officially welcoming the new citizens.
"We are pleased today that you have taken this important step in becoming a New Zealand citizen," he said.
"It's because of people like you we've become a broader and better thinking country."
Among the new citizens were the Pagaialii family of Samoa who chose to wear their traditional dress, puletasi.
Falanika Pagaialii said they had been in New Zealand about nine months and decided they wanted to "be part of the country".
She said they chose to wear their national costume to show pride in their home country.
Marie-Louise Wardell, of the Netherlands, said she had been in the country for many years and all her children were already citizens.
"I thought I better join them," she said.
American Aneta Bibby has been back and forth from New Zealand for the past 10 years.
"My husband is a citizen and my daughter and I just thought it was time to make it official," she said.
Milan and Anita Walter, of Britain, have spent most of the past eight years in Wairarapa.
"It's such a great place for kids to grow up and nice people as well," said Mr Walter.
South Korea's Paula and Jun Warren have been in the country for 10 years and made their citizenship official because "this is our home," Mrs Warren said.