Here’s what I think I know (please clarify if I’m mistaken)
(1) Alexandre de Rhodes created a Latinized script for Vietnamese in 1651. Over the centuries, the script was gradually improved, but it was mostly used for Bible translation and religious instruction.
(2) In the 19th century, France forced Vietnam to sign humiliating treaties and gradually took over more and more of its territory.
(3) Also in the 19th century, more and more Vietnamese were starting to learn chữ Quốc ngữ for their own convenience and education
(4) In 1910, all Vietnamese were required to switch over to chữ Quốc ngữ for most official purposes.
VietnamAnswer only allows a limited space for questions. Here is my detailed question and the clarifying details that I was unable to post.
My three-part question is this:
I’ll call it “X” for “unknown”. Because quốc ngữ means “National Language,” it seems unlikely that foreign missionaries would use the name quốc ngữ 國語.
B: In which year did Vietnamese people switch from “X” to “quốc ngữ”? Based on my research, I guessed 1910 or 1938.
C: Chinese people were influenced by Japan’s use of the term 國語. Is it possible that Vietnamese people were similarly influenced when choosing the name quốc ngữ 國語?
Japan started its successful self-strengthening movement in the Meiji Period (latter half of the 19th century). Japanese scholars visited the West, and on their return the government established a western-style parliament and school system, laid its own railroads, electrified major cities and built up a powerful army that was able to defeat much larger nations: Russia and China.
I imagine, but I have no hard evidence that Japan’s success may have provided a reference model for other Asian countries, as detailed in this post: Robert Matthews (馬學進)'s answer to What is Mandarin called in the Chinese language? I've heard it call "the National language" but is that what it's actually called in China? The ethnic people who spoke "Mandarin" named it "the National Language" from the get go?
I spent about 90 minutes reading sources in English, French, Chinese and Russian (some of the languages I know). I also tried to read Vietnamese sources with the aid of Google Translate (Yes, I know it’s often laughably wrong, but I was only looking for one specific fact).
[Wikipedia text] Theo tư liệu trong "Lễ kỷ niệm 70 năm Ngày thành lập Hội Truyền bá Quốc ngữ (25/5/1938)" do Bộ Giáo dục và Đào tạo tổ chức ngày 25/5/2008, thì Hội ra đời ngày 25/5/1938, đến ngày 29/7/1938, Thống sứ Bắc Kỳ công nhận sự hợp pháp của Hội. Đó là dấu mốc chắc chắn cho vị thế " chữ Quốc ngữ ".
[Google Translation] According to the document in the "70th Anniversary Ceremony of the foundation of the National Association for the Promotion of the National Language (May 25, 1938)" organized by the Ministry of Education and Training on May 25, 2008, the Association was born on May 25, 1938, to July 29, 1938, Governor of Tonkin recognized the legitimacy of the Association. That is a sure sign for the position of the "Quoc Ngu word" .