At the Boston end, the earliest predecessor was the Norfolk County Railroad, chartered April 24, 1847.
The line from the Boston and Providence Railroad's branch at Dedham, Massachusetts southwest to Walpole opened on April 23, 1849, and an extension to the Providence and Worcester Railroad in Blackstone opened May 16.
The company went bankrupt soon after.
The short Medway Branch Railroad was leased in 1851, opening December 29, 1852.

On May 1, 1849 the Southbridge and Blackstone Railroad was incorporated to extend the line west from Blackstone to Southbridge.
On its way to Douglas, this railroad passed through Ironstone, where there was a factory that made Kentucky Blue Jeans, and a nearby iron forge.
The Midland Railroad was incorporated May 2, 1850 to build a new entrance to Boston, merging with the existing one south of Dedham.
The two companies were consolidated with the Norfolk County Railroad on December 12, 1853 to form the Boston and New York Central Railroad, which had the intent of continuing southwest through Connecticut all the way to New York City.
The first section of this extension was incorporated in May 1853 as the East Thompson Railroad, forming the Connecticut portion of the Southbridge and Blackstone.

The extension from Blackstone southwest to Mechanicsville, Connecticut on the Norwich and Worcester Railroad was completed in 1853.
In January 1855 the new main line to Boston was opened, but was closed six months later until December 1856 because of an injunction due to the danger of the numerous grade crossings.
The new line ran to a terminal at the foot of Summer Street in downtown Boston via South Boston.
The full line was first operated as one on June 1, 1855, but again failed quickly.
On August 6 operations were restarted on only the original Dedham-Blackstone line, operated by the Boston and Providence Railroad as a branch.
On March 2, 1857 the trustees took repossession, ending the operation by the B&P. The East Thompson Railroad leased the line, reopening it again in full for about a year before another failure.
At that time, all but the original Dedham-Blackstone line and Medway Branch were closed until 1867.
The closed lines were sold in November 1858 to the Midland Railroad, but were not operated due to bad condition.
The Midland Land Damage Company tried again in 1862, changing its name to the Southern Midland Railroad in 1863 without success.
At the Boston end, the earliest predecessor was the Norfolk County Railroad, chartered April 24, 1847. The line from the Boston and Providence Railroad's branch at Dedham, Massachusetts southwest to Walpole opened on April 23, 1849, and an extension to the Providence and Worcester Railroad in Blackstone opened May 16. The company went bankrupt soon after. The short Medway Branch Railroad was leased in 1851, opening December 29, 1852.
On May 1, 1849 the Southbridge and Blackstone Railroad was incorporated to extend the line west from Blackstone to Southbridge. On its way to Douglas, this railroad passed through Ironstone, where there was a factory that made Kentucky Blue Jeans, and a nearby iron forge. The Midland Railroad was incorporated May 2, 1850 to build a new entrance to Boston, merging with the existing one south of Dedham. The two companies were consolidated with the Norfolk County Railroad on December 12, 1853 to form the Boston and New York Central Railroad, which had the intent of continuing southwest through Connecticut all the way to New York City. The first section of this extension was incorporated in May 1853 as the East Thompson Railroad, forming the Connecticut portion of the Southbridge and Blackstone.
The extension from Blackstone southwest to Mechanicsville, Connecticut on the Norwich and Worcester Railroad was completed in 1853. In January 1855 the new main line to Boston was opened, but was closed six months later until December 1856 because of an injunction due to the danger of the numerous grade crossings. The new line ran to a terminal at the foot of Summer Street in downtown Boston via South Boston. The full line was first operated as one on June 1, 1855, but again failed quickly. On August 6 operations were restarted on only the original Dedham-Blackstone line, operated by the Boston and Providence Railroad as a branch. On March 2, 1857 the trustees took repossession, ending the operation by the B&P. The East Thompson Railroad leased the line, reopening it again in full for about a year before another failure. At that time, all but the original Dedham-Blackstone line and Medway Branch were closed until 1867. The closed lines were sold in November 1858 to the Midland Railroad, but were not operated due to bad condition. The Midland Land Damage Company tried again in 1862, changing its name to the Southern Midland Railroad in 1863 without success.
New York and New England Railroad