Complex sentence: The ultimate result of the Act was the creation of the modern National Guard Bureau which is the federal instrument responsible for the administration of the National Guard established by Congress as a joint bureau of the Department of the Army and the Department of the Air Force.
Split into simpler sentences: The ultimate result of the Act was the creation of the modern National Guard Bureau which is the federal instrument responsible for the administration of the National Guard. Established by Congress as a Joint Bureau, of the Departments of the Department of the Army and the Department of the Air Force.