[4] Named after United States Founding Father Oliver Ellsworth, it contains historic buildings and other points of interest, and is close to Acadia National Park.

History George J. Varney, in the "Hancock County, Maine" section of his Gazetteer of the State of Maine, published in Boston in 1886, wrote: The first European who made definite mention of the Penobscot Bay and river, which wash its western side, was Thevet, a French explorer, in 1556.

Thus the two leading powers of Europe became adverse claimants of the soil of Hancock County, and the wars these claims occasioned kept the county an almost unbroken wilderness during the provincial history of Maine.It is likely that the French who founded a colony at Somes Sound on Mount Desert Island in 1613, under the patronage of Madame de Guercheville, explored the Ellsworth area and what is now the watershed of the Union River.

Varney believes that there were French settlements of some kind or another as close to Ellsworth as Trenton, Oak Point, Newbury Neck and Surry.

After the 1763 signing of the Treaty of Paris by the governments of the United Kingdom, France, Spain and Portugal, Ellsworth became part of the Commonwealth of Massachusetts.

The modern history of Ellsworth begins with the settlement of the Union River area around 1763 by a party of English led by entrepreneurs Benjamin Milliken and Benjamin Joy, from present-day southern Maine and New Hampshire, who intended to build dams and sawmills to exploit the area's timber and water power.

They applied for grants offered by the Commonwealth of Massachusetts to encourage settlement of the Hancock County area.

Historian Albert H. Davis in his History of Ellsworth, Maine, published in Lewiston, Maine, in 1927, relates what is known of this early expedition and points to the northern end of the present Water Street, just to the south of the present bridge across the Union River, as the site of the earlier crude buildings erected by the pioneers.

The surveys were made by Samuel Livermore; and as there were three of the townships on each side of the river, it gave rise to the name which the stream now bears.In 1773 the first schooner was built at Ellsworth.

The vessel carried pine shingles and oak staves in annual voyages to the West Indies.

In the years up to the beginning of the 20th century, many schooners of various sizes were built in Ellsworth shipyards along the Union River.

That name having been already taken by a settlement in present-day Oxford County, Maine, the town was incorporated by the Commonwealth of Massachusetts in 1800 as Ellsworth, named for Oliver Ellsworth, the Connecticut delegate to the 1787 National Convention that was then working on a Constitution for the new United States of America, and later the third Chief Justice of the Supreme Court.

Davis reports that in the late 1770s, there were British raids on the Union River Settlement, with attempts to appropriate local cattle.

Military training was held in front of the county buildings on Bridge Hill, west of the Union River, at the site of the present Civil War Monument.

The disputed city elections in 1896 resulted in the appointment of two separate Ellsworth police forces, each of which threatened to arrest the other.

The Great Fire of 1933 destroyed most of Ellsworth's downtown commercial district, on the east side of the Union River.

The 1960s and 1970s saw the development of an Ellsworth business district on High Street, which is the direct route to and from Bar Harbor and Acadia National Park.

As much of Maine winters are harsh and snowy throughout the season, even being at latitudes similar to southern France, such discrepancies are due to the western patterns and the Labrador Current.

[8][9] In places to the northwest of the city, as around Branch Lake, the USDA hardiness zone is 5a, while in the urban area it is 5b, as is much of the state's coastline.