The road splits as it passes under the tracks of the MBTA Red Line rapid transit route at what was previously Popes Hill Station of the Old Colony Railroad.

[5] Morrissey Boulevard proceeds north past the Richard J. Murphy Elementary School and is flanked by heavy commercial development over the following 0.5 miles (0.80 km) to Freeport Street.

[9] The road was designed as early as 1906 as an urban parkway to be constructed along the route of the Old Colony Railroad to give travelers to Quincy and Massachusetts South Shore locations a way to bypass city streets.

[11] The originally proposed route paralleling the railroad was changed and moved to the shore of Dorchester Bay on the Atlantic Ocean due in part to land reclamation efforts prior to completion of the road.

Old Colony Parkway was renamed William T. Morrissey Boulevard in 1951 in honor of the former head of the Metropolitan District Commission (MDC), now the Massachusetts Department of Conservation and Recreation (DCR).

[20][21] In July 2021, the National Oceanic and Atmospheric Administration (NOAA) released a report estimating that Boston would experience 11 to 18 days of high tide flooding in the following year.

[27][28] In December 2024, the DCR announced that it was planning to install a new pump station along the Neponset Greenway extension to reduce flooding along Morrissey that it estimated would cost $3 million.

[29] In February 2022, Massachusetts Governor Charlie Baker announced an $8.2 million project to construct a 0.7-mile shared-use path from Tenean Beach on the Neponset River Reservation to Morrissey Boulevard and that will connect the Lower Neponset River Trail with the Boston Harborwalk via Morrissey (including a 670-foot boardwalk in the salt marshes near the National Grid gas tank) would be included in the $9.5 billion in federal funds the state government received under the Infrastructure Investment and Jobs Act.

[30][31] In November 2022, the Michaels Organization announced an agreement with state officials for maintenance of the Morrissey-Neponset walking trail connection at a virtual public meeting for a proposal to redevelop the Ramada hotel property at 800 Morrissey into housing.

[34] In February 2023, MassDOT officials announced that a project to replace the Beades Bridge had been greenlighted to proceed to a design phase (to be performed by the management and consulting firm WSP) and estimated that the project could cost as much as $122 million (and with its construction not expected to begin until at least 2028), after the Department sent a letter to Boston Chief of Streets Jascha Franklin-Hodge, Massachusetts State Senator Nick Collins, and Massachusetts State Representative Daniel J.

[37] In March 2021, the administrations of Charlie Baker and Marty Walsh announced a $1 million infrastructure study to improve the Morrissey Boulevard corridor and Kosciuszko Circle,[38][39] which received its funding from the MassDOT and the Boston Planning & Development Agency (BPDA) in July 2021.

[44] In August 2022, Governor Baker signed into law an $11 billion transportation infrastructure bond bill that included $250,000 for improvements to the tide gates at Patten's Cove and that established a commission scheduled to assemble later in the same year and issue a report with findings and recommendations to improve the Morrissey Boulevard corridor and Kosciuszko Circle by June 1, 2023 (and that would include multiple state agency executives, the Mayor of Boston, state and local legislators, or their designees).

[66][67][68] In June 2012, members of the Clam Point Civic Association unanimously passed a motion declaring opposition to the construction of a billboard at the Expressway Motors Toyota car dealership at 700 Morrissey.

[70] In May 2018, the U.S. Treasury Department approved a request submitted by Massachusetts Governor Charlie Baker at the recommendation of the Walsh administration that the Columbia Point census tract, which includes the segment of Morrissey Boulevard north of Patten's Cove and the UMass Boston entrance, be designated as an opportunity zone under the Tax Cuts and Jobs Act.

[75][76][77] In March 2020, Accordia filed a 3-page letter of intent with the Boston Planning & Development Agency (BPDA) for its Bayside Expo Center redevelopment proposal.

[88] In October 2012, Herb Chambers Companies announced its intention to purchase the former WLVI television station at 75 Morrissey from WHDH and convert it into a BMW car dealership.

[89] In November 2012, the BRA announced a public meeting to be held the following month at the Cristo Rey Boston High School to discuss the Herb Chambers WLVI station proposal,[90] where Herb Chambers and Boston City Councilor Frank Baker spoke in defense of the project while Baker also expressed concerns about the effects of the project on the Columbia Point master plan.

[91] In July 2016, Herb Chambers proposed an 80,000-square foot Jaguar and Land Rover car dealership in a 5-story building at 75 Morrissey at a Columbia-Savin Hill Civic Association meeting.

[92] During a meeting with a BRA official in September 2016, Columbia-Savin Hill Civic Association members expressed opposition to the Herb Chambers 75 Morrissey proposal.

[98] In October 2019, Center Court announced a revised proposal for 75 Morrissey to the Columbia-Savin Hill Civic Association that reduced the height of the buildings to 15 and 17 stories.

[105] In early 2023, Center Court entered into an agreement with The Record Co. to convert the facility at 55 Morrissey temporarily into a music rehearsal space for local musicians with 88 rentable studios.

[107] In December 2024, Copper Mill and POB Capital of Chicago filed a letter of intent with the BPDA that stated that they would submit a plan for public review within 60 days for the 35–75 Morrissey properties to construct only two buildings with 750 housing units and reduced life science space and that made no mention of Center Court or its company officials.

[108] In January 2025, Copper Mill's CEO stated at a Columbia-Savin Hill Civic Association meeting that the company intended to follow the master plan for the property approved by the BPDA in 2023.

[135] In November 2022, Beacon and the Massachusetts Biotechnology Council announced that the latter would create a 4,000 square foot training center featuring three certificate programs for prospective technicians and lab assistants at Southline Boston.

[136] In March 2023, Beacon filed a project change notice with the BPDA for the additional 6-story building at 135 Morrissey to include a skyway connecting the new building with the main facility and more office space,[137][138] while Portal Innovations, a Chicago-based biotech venture capital firm, announced that it would open a location at Southline Boston in partnership with Beacon and ZoE Life Sciences.

[142][143] In October 2012, Synergy Investments announced a $60 million proposal to the Boston Redevelopment Authority (BRA) to construct two 5-story buildings with 278 units of rental housing at 25 Morrissey.

[152][153] In November 2021, the BPDA announced a public meeting scheduled for the following month to review a proposal to redevelop the Ramada hotel at 800 Morrissey also owned by Phillips Family Properties into a 6-story residential building with 240 units.

[158][159][160] In an interview with the Dorchester Reporter in the same month, Boston Mayor Michelle Wu did not commit to supporting the 900 Morrissey proposal due to its stage of development (but stated that more supportive housing was needed in the city and praised the Pine Street Inn as a homeless service provider),[161] while the Dorchester Reporter itself published an editorial in favor of expediting the proposal's BPDA review process.

[186][187] In November 2018, Herb Chambers Companies announced that it would move its Honda car dealership from Commonwealth Avenue in Allston to 720 Morrissey the following year.