The New York, New Haven and Hartford Railroad Company, commonly known as the New Haven Railroad or simply, 'The New Haven', operated in the states of New York, Connecticut, Rhode Island, and Massachusetts. The New Haven operated freight and passenger trains over a Boston - New York City main line and a number of branch lines.

At various points in time, the New Haven Railroad owned trolley companies, truck companies, bus companies, and steamship companies. During the early 1940s the New Haven Railroad even tried to start an airline subsidiary! The New Haven was one of the few railroads in America to operate steam, diesel, and electric locomotives at the same time. In its day, the New Haven was generally considered the largest and most important transportation enterprise in New England.

The New Haven Railroad was formed in 1872 when the New York & New Haven and Hartford & New Haven railroads were merged together to form the New York, New Haven and Hartford Railroad Company. The New Haven's early management focused on expanding the company through an aggressive policy of mergers and acquisitions. Consequently, by the turn of the century the New Haven had absorbed over 25 railroad companies, dramatically expanding from its original 450 route miles to over 2,047 miles of trackage.

The New Haven Railroad was always a technologically innovative company. Early experiments in electrification were performed on several branch lines during the 1890s. These experiments resulted in the entire main line from New York City to New Haven, Connecticut being put under catenary wires by 1914. Additionally, the New Haven Railroad's turn of the century car and locomotive shops at Readville, Ma. were among the first large industrial plants in America to be designed to take advantage of scientific work management principals.

Around the turn of the century, the New Haven Railroad came under the control of J. P. Morgan, the notorious financier. Morgan set out to build a complete New England transportation monopoly using the New Haven Railroad as his cash cow and base of operations. On J. P Morgan's orders, the New Haven bought up hundreds of railroads, steamship lines, and trolley companies throughout New England.

By 1910, J. P. Morgan's monopoly building efforts, which were in violation of various federal and state anti-trust laws, came under direct criminal investigation. Additionally, Morgan had so over-extended the company that it came very close to financial collapse. The war in Europe was the only thing which kept the New Haven Railroad out of bankruptcy at that time. During World War One, the New Haven was taken over by the federal government and operated by the United States Railroad Administration (USRA). The various 'war emergency' protections afforded the railroad by the USRA and the great influx of military related business put the New Haven back on its feet again.

In 1920, the New Haven Railroad reverted back to civilian ownership. The generally favorable business climate of the 1920s permitted the railroad's new management to rebuild worn out equipment and infrastructure. Significant accomplishments by the New Haven during the 1920s included the modernization of a huge fleet of old wooden boxcars and the establishment of a bus and trucking subsidiary called 'The New England Transportation Company'.

The 'Great Depression' of the 1930s brought the New Haven Railroad once again to the brink of insolvency. In 1935, the New Haven's financial condition deteriorated to such a degree that president Howard S. Palmer petitioned the bankruptcy court for reorganization under section 77 of the bankruptcy laws to shield the troubled railroad from its creditors. Under bankruptcy protections the New Haven persevered and even managed to make some progress during this time of great trouble. During the 1930s, the New Haven Railroad introduced the very first streamlined passenger train to New England, the unique Goodyear Zeppelin 'Comet'. The New Haven also bought its first diesel switchers and modern lightweight passenger cars during the depression years. Additionally, the New Haven bought a small fleet of streamlined steam locomotives, streamlined electric locomotives, and initiated one of the first large scale piggyback freight operations during the 1930s.

The Second World War introduced the New Haven Railroad to the concept of mass dieselization. The then new Alco/GE DL-109 diesel passenger locomotives, which the New Haven bought in greater numbers than any other railroad, were used in round the clock service on passenger trains during the day and on freight trains at night. The New Haven was considered so important to the war effort that the War Production Board (WPB) actually released enough rationed materials to permit the railroad to obtain additional diesel and electric locomotives during the war years.

Wartime research and development efforts conducted by the New Haven Railroad under principal trustee Howard Palmer positioned the company to immediately purchase a large fleet of new diesel locomotives and streamlined passenger cars as soon as the war ended. Consequently, by the late 1940s the New Haven could boast one of the most modern passenger train fleets in the country. Howard Palmer's modernization programs, along with the dramatic increase in traffic caused by the war, brought the railroad out of bankruptcy during 1947. The next year, financier Frederic C. Dumaine Sr. took control of the New Haven Railroad, throwing Howard Palmer out of the president's seat. The tight-fisted elder Dumaine put the New Haven through an austerity program which among other things resulted in the dismissal of all employees who earned over $10,000 per year!

In 1951 Frederic C. Dumaine Sr. died and his oldest son Frederic C. Dumaine Jr., who was called 'Buck', became president of the railroad. The 1950s decade was a time of change and transition for the New Haven. Three different management teams purchased a variety of passenger and freight equipment from a number of different suppliers, causing supply and maintenance headaches and draining cash reserves. Some New Haven Railroad innovations of this era, such as the new parking lot passenger station established at Route 128 near Boston and the Rail Charge Card, were great successes. Other New Haven innovations such as the Mack FCD rail busses and Clejan piggyback flatcars, were great failures. The short-lived and controversial administration of president Patrick McGinnis, which commenced during April 1954 and was over in January 1956, put the New Haven through a comprehensive corporate image design project which gave the railroad a new 'NH' logo and red, white, and black corporate color scheme. The New Haven's president during the latter half of the 1950s, George Alpert, was an early champion of government subsidies for money-losing railroad passenger operations and purchased the unique dual-powered EMD FL-9 diesel-electric-electric locomotives.

Expensive hurricane and flood damage during 1954 and 1955, competition from government subsidized highways and airlines, high rates of taxation, enormous commuter service losses, and the out-migration of heavy industry from New England to the south and west caused the New Haven Railroad to go bankrupt again in 1961. After a decade of struggling along under trustees Richard Smith, William Kirk, and Harry Dorrigan, the New Haven Railroad was absorbed by the ill-fated Penn Central Transportation Company on January 1st, 1969.