During the scene where the women discuss the US entering WWI while at a restaurant, Lucy is shown from behind gesturing with her fork in her hand. When the shot switches to in front of her, her hand hasn't changed positions but the fork is no longer there.
Although the final scene is said to take place in August, it's clearly late autumn (Lucy and Alice wear coats and trees are obviously losing their leaves).
When Alice is learning how to drive, her mouth is repeatedly open/closed between shots.
In the scenes where Ben is teaching Alice to drive, in close up shots she can barely see over the steering wheel, in far away shots she's of normal height.
Inez Milholland's funeral in reality was quite large. It was held in Statuary Hall in the US Capitol on Christmas Day 1916. Alice Paul carried the banner Inez had carried during the suffrage parade and the women of the NWP drafted petitions to President Wilson regarding the suffrage amendment.
Despite what is portrayed in the movie, Carrie Chapman Catt never reconciled with Alice Paul. They remained rivals in the feminist movement for the rest of their lives.
When Pres. Wilson is giving the speech in Congress, the US flag is hung backwards. Whether the flag is vertical or horizontal, the stars should always be in the upper left.
Doris Stevens continually says she's working for the "National Woman's Suffrage Association" when the movie starts out in 1912. However, the National Woman Suffrage Association merged with the American Woman Suffrage Association in 1890 to become the National American Woman Suffrage Association (NAWSA).
During President Wilson's speech acknowledging the importance of women to the war effort, the flag behind him is hanging incorrectly, The Union -- the blue field -- should always be displayed in the upper left-hand corner. In the film it's to the right.
50-star US flags throughout most of the first half of the movie.
There are numerous historical inaccuracies including women's hair and men's clothing styles, the presence of a small woman's wrist watch and of a Crown Graphic press camera, both of which did not exist in 1918.
Hillary Swank (Alice Paul) is drinking from a Jeannette and Herringbone clear iris cup. Although the company existed in 1898, the clear cups weren't introduced until 1928.
When Alice Paul goes to meet Ben Weissmen at the restaurant, the front door has a modern door handle.