The Historian David Cohen found that early settlers in the Hackensack Valley included "free black landowners in New York City and mulattoes with some Dutch ancestry who were among the first pioneers to settle in the Hackensack River Valley of New Jersey." Among these were Augustine Van Donck, who bought land in the Tappan Patent in 1687. As the border between New York and New Jersey split the area of the patent in 1798, Cohen theorized that some of these early free people of color moved west into the mountains. (The surname Van Dunk is Common among the Ramapough, as are DeGroat, DeFreese, and Mann.) Cohen thought that, while some free blacks may have married Lenape remnant peoples in the area, the residents of the mountains developed not primarily of Indian culture but as multiracial people of European-American culture, with rural traditions. The origin of these Surnames could also be from earlier contact times with the Colonials. In the late 19th century, such Indians were said to use the names given by the Colonials instead of their real names because of superstition.

In the early 1700s, the Ramapo in present-day western Connecticut were led by a sachem or chief named Katonah. Under pressure from English colonists, they sold their land in the Ridgefield area, a territory estimated at 20,000 acres (81 km), and moved away. The Ramapo migrated west and some eventually settled in the mountains in northeastern New Jersey and southwestern New York; this part of the Appalachian Mountains was named for them by colonists as the Ramapo Mountains.

Wynant Van Gelder, the first European landowner in what became Sloatsburg in Rockland County, New York, was noted as having bought land from the Ramapough in 1738. Ramapough Mountain Indians still live in the county, especially in Hillburn, New York

Kraft noted, as did Cohen (see below), that there was a gap in "the genealogical record between about 1790-1830 that prevented his assembling with exactitude individual relationships between most of the Hackensack Valley settlers and those of the Ramapo Mountains." In his own work, Kraft has not attempted to establish genealogical links between the present-day Ramapough and colonial-era Indian tribes.

Before 1870, the State of New Jersey Census had only three racial or ethnic categories for residents: White, Black (free), and Black (slave), the same categories as were used in the slave states. Census enumerators tended to use black as the category for any people of color, including Indians. New Jersey passed a gradual abolition law in 1804 to end slavery; children born to slave mothers were born free. The state retained slaves born before the law in an indentured status. By a law of 1846, it reclassified them as apprentices, "apprenticed for life." The last slaves in New Jersey were not freed until 1865 and passage of the Thirteenth Amendment. In 1870, New Jersey began recording Indians (Native Americans) as a separate category in its census; 16 were identified by census enumerators that year.

The group rejects this name and its associated legends as pejorative. On July 30, 1880, The Bergen Democrat was the first newspaper to print the term Jackson Whites. A 1911 article noted it was used as a title of contempt. Instead, they called themselves "The Mountain People."

The Ramapo were a Munsee-speaking band of the Lenape, an Algonquian language-speaking people who occupied a large territory throughout coastal areas of the mid-Atlantic states and along the Delaware River valley. Bands were typically named after their geographic region. Early European colonists thought they were different peoples, but all were Lenape. Ramapo villages were recorded in the late seventeenth century in western Connecticut, near present-day Bethel and Ridgefield. In 1911 an intact dugout canoe was found underwater near Bethel and identified as possibly Ramapo; it is now held at the Connecticut State Museum of Natural History at the University of Connecticut. In 1923 Foster H. Seville, an ethnologist, authenticated two dugout canoes found in Witteck Lake, near Butler, New Jersey, as of Ramapo origin and possibly 1,000 years old. They were exhibited in the American Museum of Natural History and in Hackensack, New Jersey.

In the twentieth century, some anthropologists Classified such isolated mixed-race groups, who tended to be historically endogamous, as tri-racial isolates or simply as mixed Bloods. Alanson Skinner of the American Museum of Natural History in 1915 noted the multiracial character of the people in the Ramapo Mountains. He said that Indian descendants had mixed with Africans and Caucasians.

Members of the community have participated in litigation (Mann v. Ford) against the Ford Motor Company regarding poisoning from a former toxic waste landfill. Portions of this site were used in the 1970s as sites for affordable housing for the Ramapough people.

Cohen noted in 1974 that, as the federal censuses of 1790-1830 were missing for this area, it prevented "establishing positively the exact relationship between many of these colored families in the mountains, and the earlier colored families of the Hackensack River Valley." He noted the "tradition of Indian ancestry among the Ramapo Mountain People as early as the eighteenth century." Cohen also said, "Some Indian mixture is possible; however, Indian and colored interracial matings probably were not recorded in the Dutch Reformed Churches."

John "Bud" Shapard was the former chief of the Bureau of Research at the BIA from 1978-1987, when the regulations were written. Asked to review the Ramapough's case after the BIA declined their petition, in 1999 he said, "It's pretty clear they've got an Indian community as strong as some that have been recognized. There's no question about that."

The Ramapough Indians claim to have been recognized by the State of New York by Legislative Resolution 86 in 1979. According to Alexa Koenig and Jonathan Stein, who have reviewed state recognition processes, New York does not have an official, separate process of recognition of Indian tribes and never recognized the Ramapough. It recognized the Shinnecock and one other tribe under independent criteria.

In the 1980s, the Environmental Protection Agency designated the Ringwood Mines landfill site as a Superfund site for cleanup. Ford had operated an auto assembly plant in Mahwah and its contractors dumped industrial paints and other Hazardous wastes in a landfill owned by the company in an area where many Ramapough Mountain Indians live. The EPA identified further remediation three more times as additional sludge sites were found. Following further investigation, The EPA returned the community to the Superfund list, the only site to be so treated.

With increasing interest and research in Native American history, a 1984 symposium was held on the Lenape. James Revey (Lone Bear), then chairman of the New Jersey Indian Office, said that "Mountain Indians" were descendants of Lenape who had retreated into the mountains of western and northeastern New Jersey and southwestern New York during the colonial era. Other scholars, such as Herbert C. Kraft, have documented that some Munsee-speaking Lenape moved into the Ramapo Mountains to escape colonial encroachment.

The Ramapough Mountain Indians submitted its petition for recognition with supporting documentation in 1990. Roger D. Joslyn, a certified genealogist and one of the consultants to the tribe in this process, has traced Ramapough members to people of the 18th century. He concluded that tribal members were descended from the historical Munsee tribe.

The BIA gave the Tribe an opportunity to respond to its Proposed Finding of December 8, 1993, which said its documented petition did not satisfy all the regulatory criteria. It identified areas of weakness and provided extensions requested by the Tribe. Finally in December 1995, the agency issued its Final Determination, which concluded that the Ramapough Mountain Indians had failed to meet three of seven criteria for recognition; namely, that it did not provide adequate proof of descent from a historical tribe, nor of genealogical, social and political continuity since 1950. The latter two issues were of concern since 1950, when the BIA felt that the tribe had not demonstrated a distinct Indian culture different from its neighbors. They said:

In 1995, New Jersey established a Commission on American Indian Affairs (then called the Commission on Native American Affairs) with two seats each for the recognized tribes of the Ramapough Mountain Indians, the Nanticoke Lenni-Lenape, and the Powhatan Renape (the latter two groups are located in southern New Jersey.) In addition, two seats were reserved for Inter-Tribal Members, persons who belonged to other tribes but lived in New Jersey. The Commission has been placed in the Department of State.

Edward J. Lenik, an Archeologist and author of a 1999 book about the Ramapo Indians, writes:

The Ramapough, who are opposed to gambling, appealed the BIA's decision. On November 2001, the Ramapough presented their case to the Court of Appeals. The BIA conceded that the Ramapough are Native American:

In late winter 2006, some 600 Ramapough Lenape Indians, led by Wayne Mann and with the aid of Robert F. Kennedy, Jr., filed a mass tort suit (Mann v. Ford) against the "Ford Motor Company and its contractors, as well as the borough of Ringwood, for the dumping of toxic waste." They were represented by Vicki Gilliam of The Cochran Group. The suit was filed about the time of publication of Toxic Legacy, a five-part investigative series by The Record, which had found lead and antimony levels in excess of 100 times the safety limit near some Ramapough residences.

In August 2006, Governor Jon Corzine formed the New Jersey Committee on Native American Community Affairs to investigate issues of civil rights, education, employment, fair housing, environmental protection, health care, infrastructure and equal opportunity confronting members of New Jersey's three indigenous Native American tribes and other New Jersey residents of Native American descent. The Committee's report was delivered on December 17, 2007 and cited "lingering discrimination, ignorance of state history and culture, and cynicism in the treatment of Indian people".

In 2009 the New York legislature had a bill pending to recognize the Ramapough people as Native Americans. It never was passed.

State and federal officials have worked with the tribes on other issues related to their people. For instance, in preparation for the 2010 census, state and federal officials consulted with the recognized tribes on means to get accurate counts of their people. The Census Bureau has created local partnerships. It recognizes State Designated Tribal Statistical Areas (SDTSA), which are established by state consultation with local tribes to identify significant areas of American Indian populations outside reservations (these had been overlooked in the twentieth century). In New Jersey, these are identified as Passaic and Bergen counties for the Ramapough Mountain Tribe, and Cumberland County for the Nanticoke Lenni-Lenape. The Rankokus Indian Reservation no longer qualifies, as the state has taken back much of the land it had earlier leased to the Powhatan Renape.

The EPA has directed the removal of an additional 47,000 tons of sludge and soil up to 2011, with cleanup continuing.

The line would also pass through the Ramapo Mountains and Ramapo Pass. In solidarity with Standing Rock, tribal members founded the Split Rock Sweetwater protest encampment in Mahwah, New Jersey in 2016 near the New York border to protest the Pilgrim Pipeline.

As of 2017, the tribe is fighting against the Pilgrim Pipeline. Pilgrim Pipelines Holdings, LLC plans to run a duel pipeline through the tribe's land which would carry refined products like gasoline, diesel, Kerosene, aviation fuel and home heating oil north and Bakken formation crude oil south between Albany, New York and the Bayway Refinery on the Chemical Coast in Linden, New Jersey.

European Americans assumed that Indians wanted only to assimilate to the majority culture and that intermarriage meant a weakening of their cultures; in addition, racism associated with slavery tended to classify people of mixed-race as black rather than Indian, regardless of their cultural affiliation. Whites in the Northeast assumed that Indian cultures had largely ended after centuries of interaction with European Americans. By contrast, numerous Native American tribes had a historic tradition of absorbing other peoples by marriage or adoption; people brought up within their cultures generally identified as Native Americans of particular tribes. Thus, during the period of urbanization, high rates of immigration, and suburban development throughout the New York metropolitan area in the late 19th and early 20th centuries, the Ramapough Mountain Indians continued to live in their historic areas of settlement in the mountains and there maintained a rural culture.