Complex sentence: O'Sullivan, Dudley, and Scudder were among the founding members of the Women's Trade Union League in 1903, and during Dudley's tenure several trade unions met regularly at Denison House.
Split into simpler sentences: O'Sullivan, Dudley, and Scudder were among the founding members of the Women's Trade Union League in 1903. During Dudley's tenure several trade unions met regularly at Denison House.