The film is a prime example of the emotional mood swings that energized Ford's films.
But it also showcases the director's eye for composition and use of Nature to re-inforce story points. For example, there's this early scene where Abe and Anne tentatively express feelings. Anne is friendly with Abe, while he is tragically smitten. Ford frames them by a river where a great tree forms an arch extending from Anne and branches out to barely graze Abe.
The scene will end with Lincoln walking under that arch, alone, and throwing a rock into that swiftly-flowing river, its ripples starting a transition in time that will show the river clogged with ice, and a graveyard containing Anne's grave. In the background, a yearning violin piece serves as "her" theme, but also, generally, of memory and loss, as it keeps coming back throughout the film (23 years later, Ford would use it again in the same context in "The Man Who Shot Liberty Valance.")
And there's no denying the power of that almost-final shot (a more obvious studio shot serves as the last one, followed by Lincoln Memorial views) of Lincoln's film-ending hill-climb "goin' on a-piece." The bordering fence forming a barricade and the huge sky rumbling with thunder. It's one of the most beautiful representations of Destiny ever committed to film, from the film-laureate of History and nostalgia with a painter's eye and a poet's command of metaphor.