NY line at Stockbridge to East Boston via Springfield and Framingham.
Expressway full length; toll highway.
The Mass Turnpike first opened on May 15 ,1957 from the New York state line to MA 128.  Construction began January 4, 1955, with the 123 mile mainline road being split into 133 separate contracts . The toll from West Stockbridge to Weston was $2.45 and the speed limit was 60 MPH.
The road was designated I-90 in 1959. In 1964, the Boston Extension was opened between 128 and the Allston-Brighton tolls. It was extended to the Central Artery Expressway on Feb 18, 1965. The toll increased to $3.00 for and end-to-end trip due to the extra length. The Boston Extension cost nearly as much as the entire rest of the road ($240 million for the extension, compared to $257 million for the main section). 
In 1969, exit 11A was created for I-495 and the speed limit was increased to 65 MPH. By 1969, tolls had edged up slightly, to $3.30 for the full length. The increases over the original toll were 5 cents for each segment between Lee (Exit 2) and Weston (exit 14), except for Palmer to Sturbridge which remained at 30 cents.
In 1974, the federal government passed the National Maximum Speed Limit law which basically set a cap on speed limits at 55 MPH. By 1979, tolls had gone up again. A trip from end to end would now cost $4.30. Tolls increased from 5 to 20 cents per segment.
Tolls were eliminated for passenger cars west of exit 6 in July, 1996. 
Exit 10A opened in 1998, allowing direct access to MA 146.
The Ted Williams Tunnel was connected to the rest of I-90 via the O’Neill Tunnel in January, 2003.
 Much of the specific date information (as opposed to the “between 1961 and 1966 type of stuff”) comes from the Mass Turnpike’s official website.
 “Issue: 2002-Turnpike/Toll Increases” article on 02133.org.
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Dan Vincent’s I-90 page