The first printed literature in Sámi appeared in 1619 and marked the distinction between old and newer Sámi language. However, the unique orthography that characterises today’s Northern Sámi written language is a good deal younger. For more than 200 years, all Sámi languages were written with the same Latin alphabet as the other Nordic languages; the unique phonemes found in Sámi had to be expressed using combinations of Latin characters. An early attempt to modify Samí orthography according to linguistic principles came in 1769, when two Hungarian Jesuit missionaries first discovered that Sámi and Hungarian were part of the same language family.
The proposal to use the Hungarian alphabet to represent Sámi phonemes in a new Northern Sámi dictionary was discussed in 1770, and the Sámi linguist Anders Porsanger was largely positive when consulted about the possible change. His superior, Knud Leem (a significant person in the development of the Sámi written language) disagreed, and did not want different alphabets for Norwegian and Sámi. The new Sámi dictionary was printed without Hungarian influence. More that 60 years later, the Danish linguist Rasmus Rask revised Leem’s work and committed himself to introducing new characters for the unique Sámi sounds in his Ræsonneret lappisk sproglære (1832). Rask was an ardent supporter of phonemic orthography, i.e. the principle that the phonemes should directly correspond to the graphemes (it was in the spirit of this idea that he changed the spelling of his own surname from Rasch to Rask). Rask corresponded actively with Nils V. Stockfleth, who, in his 1837 grammar, used Rask’s graphemes in his own revision of Leem’s grammar and spelling (later known as the Stockfleth-Friis spelling). The new characters would continue to be included in future spelling reforms, but it is important to specify that Rask’s influence primarily applied to Northern Sámi (the largest Sámi language and the one most used in Norwegian context).

Although these new characters represent the Northern Sámi language more faithfully and consistently than alternative systems, challenges have arisen in modern times; the use of diacritical marks can be difficult on the internet. Especially before the UNICODE system, it was difficult to reproduce the characters digitally.
Sources
Focus on Structure · Northern Saami · Northern Saami
Grankvist, Rolf: Anders Porsanger i Norsk biografisk leksikon på snl.no. viewed 20th December 2024 at https://nbl.snl.no/Anders_Porsanger
Northern Sámi – Wikipedia (https://en.wikipedia.org/wiki/Northern_S%C3%A1mi)
Rasmus Rask – Wikipedia (https://en.wikipedia.org/wiki/Rasmus_Rask)