As was common at this time in Hollywood, the facts of the Stanley-Livingstone saga were highly fictionalized and romanticized in this film. This was an era in movie-making when close attention was not always given to historical accuracy.
The ending of the movie, with "Onward Christian Soldiers" playing in the background, turned the movie into a salute to the "spreading of Christianity to heathen lands," one of the common arguments used in the 19th century to justify European imperialism. It's another example of Hollywood portraying Christianity as the "true religion" superior to all other beliefs. On top of that, the ending clearly overlooks the fact that while Stanley returned to Africa after Livingstone's death, it was for purposes of exploration and empire building, not to follow in Livingstone's footsteps as a missionary.
The ending of the movie, with "Onward Christian Soldiers" playing in the background, turned the movie into a salute to the "spreading of Christianity to heathen lands," one of the common arguments used in the 19th century to justify European imperialism. It's another example of Hollywood portraying Christianity as the "true religion" superior to all other beliefs. On top of that, the ending clearly overlooks the fact that while Stanley returned to Africa after Livingstone's death, it was for purposes of exploration and empire building, not to follow in Livingstone's footsteps as a missionary.