Complex sentence: As an adolescent he worked in the Duquesne Steel Works, but left during the Depression to look for work in Washington D.C., where he met the social worker Ann Terry White, the wife of Treasury Department official Harry Dexter White.
Split into simpler sentences: As an adolescent he worked in the Duquesne Steel Works, but left during the Depression. One of the people he met in Washington D.C. was the social worker Ann Terry White, wife of Treasury Department official Harry Dexter White.