( It had already broken up the SP - UP combination in 1913 . )
However , work was then placed on hold while the federal government decided whether the SP 's lease of the CP violated the Sherman Antitrust Act .
( SP had already broken up the SP - UP combination in 1913 . )
However , work was then placed on hold while the federal government decided whether the SP 's lease of the CP violated the Sherman Antitrust Act .