Newburyport, Massachusetts in the context of Essex County, Massachusetts

Jacob Perkins (July 9, 1766 – July 30, 1849) was an American inventor, mechanical engineer and physicist based in the United Kingdom. Born in Newburyport, Massachusetts, Perkins was apprenticed to a goldsmith. He soon made himself known with a variety of useful mechanical inventions and eventually had twenty-one American and nineteen English patents. Sometimes known as the father of the refrigerator. He was elected a Fellow of the American Academy of Arts and Sciences in 1813 and a member of the American Philosophical Society in 1819.

The MBTA Commuter Rail (reporting mark MBTX) system serves as the commuter rail arm of the Massachusetts Bay Transportation Authority's (MBTA's) transportation coverage of Greater Boston in the United States. Trains run over 429 mi (690 km) of track on 12 lines to 143 stations. It is operated under contract by Keolis.

In 2024, the system had a ridership of 30,343,900, or about 100,200 per weekday as of the third quarter of 2025, making it the fifth-busiest commuter rail system in the U.S., behind the three New York-area systems and the Chicago-area system. The lines' characteristic purple-trimmed coaches operate as far south as North Kingstown, Rhode Island, and as far north as Newburyport and as far west as Fitchburg, both in Massachusetts.

The Merrimack River (or Merrimac River, an occasional earlier spelling) is a 117-mile-long (188 km) river in the northeastern United States. It rises at the confluence of the Pemigewasset and Winnipesaukee rivers in Franklin, New Hampshire, flows southward into Massachusetts, and then flows northeast until it empties into the Gulf of Maine at Newburyport. From Pawtucket Falls in Lowell, Massachusetts, onward, the Massachusetts–New Hampshire border is roughly calculated as the line three miles north of the river.

The Merrimack is an important regional focus in both New Hampshire and Massachusetts. The central-southern part of New Hampshire and most of northeast Massachusetts is known as the Merrimack Valley.