Bridge No: 3220002100800

Asset ID: 1965

County: Lexington

Bridge Name: Blossom Street Bridge/McMillan Bridge

Facility Carried: US 21/US 176/US 321 (Blossom Street)

Feature Intersected: Congaree River

Year Built: 1949-1953

Year Reconstructed:

Main Structure Type: Girder-floorbeam

Design: Continuous

Main Material: Steel

Railing Type: Steel balustrade panels, between concrete posts

Number of Main Spans: 13

Number of Approach Spans:

Approach Type:

Structure Length: 1467 feet

Structure Width: 56.4 feet

Setting: The bridge carries a striped, 4 lane arterial street/highway and sidewalks over the Congaree River between Cayce and Columbia.The Cayce end of the bridge is a riverside park.On the Columbia side, much of the original industrial land use has been changed.The railroad tracks have been removed, and the areas have been redeveloped.The setting does not have historic district potential.

The 13 span, 1,467'-long and 56.4' wide continuous bridge consists of 4 lines of built-up, haunched girders with a longitudinal joint at the center line that in essence creates two separate structures supported on the same piers.The paired deck girders each support rolled steel floorbeams, stringers, and a concrete deck.The bridge has two, 4-span continuous units (2 @114'-112'-113'-113'), and one, 5-span continuous unit (1 @ 113'-112'-112'-112'-113'). The beams are supported on high column bents, and those in the stream have web walls.They are accented with vertical scoring. There are 12, 50'long T beam approach spans. The cantilevered sidewalks are supported on concrete brackets and finished with steel balustrade-like railings with concrete posts that feature the same vertical scoring as the substructure.A refuge, or exedra, with a bench is located at Cayce end of the bridge adjacent to the memorial plaque.The bridge originally had standard 1950s highway lighting (metal poles with cantilevered luminaires).The current "antique" lights are a recent alteration. They replace the original sodium vapor luminaires on 115'-high poles to create "white way" lighting.

The 1949-1953 Blossom Street bridge is located between Cayce, in Lexington County, and the industrial district on the west side of downtown Columbia.Really a viaduct over local streets and railroads as well as the river, the long bridge ranks as one of the most extensive urban highway developments in the state.Planned as early as 1944 as part of the Bureau of Public Road’s (BPR) traffic master plan for Columbia, its purpose was to provide an additional crossing of the Congaree River to take some of the traffic volume off the Gervais Street bridge.It represents the type of analysis that was done by the BPR and state highway departments in the 1940s that produced the major urban congestion relief projects that got underway with the World War II stand down. Location studies for a new Congaree River crossing began in 1949, and the bridge was opened in 1953. It was built as a federal-aid project.

The need for another artery from the west was great.Until the Blossom Street bridge was completed in 1953, the Gervais Street bridge carried five highways. The new bridge carries three important US-numbered routes and a large volume of local traffic and was a key feature of the improvement of US 21 through Columbia.Its construction also involved improvements to existing streets in downtown Columbia, like Assembly Street, and a new alignment for Blossom Street in Cayce.Construction was protracted because of delays in getting the steel beams.Although the continuous girder-floorbeam type and design had been used in the state since the late 1930s and is not technologically significant, the bridge is historically significant as a complete period piece of planning and community development intended to address urban traffic and maintaining the viability of urban commercial and industrial centers (Criterion A).Prior to construction of the interstate highways starting in 1956, this is one of the transportation projects with the greatest impact on the capital city.The bridge is named for South Carolina’s long-time Chief Highway Engineer Claude McMillan.