The 1–50 series cars (numbered 1–50) were manufactured by the St. Louis Car Company of St. Louis, Missouri, and delivered to the CTA in 1959 and 1960. The cars were similar to the 6000-series design, but were double ended, single cars, as opposed to the 6000-series single ended, married pair configuration. The quarter point doors were adjacent to the operators cabs, allowing the operator to collect fares without leaving the cab. Like some members of the 6000-series, these cars utilized parts salvaged from Chicago's recently retired fleet of PCC streetcars.