Here's the roll call on GovTrack, for the vote on April 5th, 1917.

As a side-note, one of the fifty "Nay" votes was Representative Jeannette Rankin of Montana, an activist in the woman's suffrage movement and the first woman elected to Congress. A strong pacifist, she said as she voted, "I want to stand by my country, but I cannot vote for war." Her constituents by and large stood by her, but she was criticized as "a member of the Hun army in the United States, and a crying schoolgirl." She later returned to Congress in 1940, where she was the one and only member of either house to vote against the declaration of war on Japan.