Europeans arrived in a richly inhabited New World teeming with plants, animals, and people unknown to them. Often their underlying motivations, or their general poor planning, meant early attempts to found permanent settlements ended in complete failure. The list of early entradas in North America reads like a series of unfortunate events as one would-be conquistador after another lost their lives in this New World. de Leon, Narvaez, Ayllon, and de Soto all perished trying to gain fortune in the Southeast. Coronado narrowly survived his entrada into the Southwest, only to face charges of brutality against Native Americans once he returned to Mexico. Unprepared, ill-equipped, and starving in a new land, entradas pillaged their way through Native American grain stores to survive.

For the first few centuries after contact, many of the nations along the Atlantic Coast refused to allow permanent European settlements. From Florida to Nova Scotia, European traders and fishermen plied the coast, trading with coastal populations in the summer and on occasion kidnapping unwary Amerindians to sell as slaves or serve as translators. The notable exception to this trend is the early Spanish mission presence in Florida. In Florida caciques allowed Franciscan fathers to establish missions as a means of forming alliances and harnessing access to Spanish prestige goods. Florida consistently cost Spain far more money than it generated, and the entire colony depended on the food produced in the missions. There was no way for Spain to maintain such a costly colony without the support of the Guale, Apalachee, and Timucua.

The popular narrative of American history places Europeans in the driver's seat for early contact events. We often forget those early settlements only survived with the permission of neighboring Native American nations. Powhatan wanted to use the English as allies against an encroaching Spanish threat from the south. He incorporated Jamestown into his Paramount Chiefdom of over thirty nations, and chose John Smith to serve as the weroance representative of Jamestown within the larger Powhatan sphere. In Massachusetts Massasoit, sachem of the Wampanoag, reversed an earlier policy of resisting permanent settlements along the coast. He waited the winter, then approached the starving Plymouth colonists with an offer of peace in exchange for their help as allies against his inland enemies.

English colonists needed help adapting to this new world. Without Native American assistance both Jamestown and Plymouth faced massive mortality. Before Wampanoag assistance over half of the Mayflower passengers died during the first winter in Massachusetts. When a gunpowder accident seriously injured Smith, forcing his return to England, Jamestown lost their trusted intermediary with the Powhatan, and with him their access to much needed trade food. When the relationship with the Powhatan deteriorated in Smith's absence, the residents of Jamestown resorted to cannibalism during Starving Time in the winter of 1609-1610. Colonists were in the process of abandoning the outpost when they were finally resupplied.

Throughout the Americas early colonists were dependent on Native Americans. No outpost could survive in the shadow of powerful nations without assistance. Native Americans provided food, served as translators, supplied the raw and manufactured materials to make colonies profitable, and allied with European military efforts to settle old scores. Established trails and trade routes developed and maintained by centuries of Native Americans were used by early explorers to venture into the heart of the continent. Exploration along major waterways took place in the canoes built by Amerindians, often propelled by Amerindians, and most certainly aided and directed by Amerindians. The vital influence of Native Americans in the history of our country goes far beyond the possibly apocryphal story of Tisquantum showing Plymouth colonists how to use fish fertilizer. Every step of our history as a series of colonies, and then as a new nation, was influenced and shaped by the interaction and negotiation between Europeans and Native Americans.

Edit: For solid introductions to this topic check out Richter's Before the Revolution: Americas Ancient Pasts and Facing East From Indian Country. Also, I can't recommend Calloway's One Vast Winter Count: The Native American West Before Lewis and Clark highly enough. Such a great book.

The pilgrims that came to America had come and had a hard first winter. 45 of the 102 died during the first winter. (Mostly for scurvy and pneumonia)

The most common story is that Squanto (Tisquantum) taught the struggling pilgrims to more successfully fertilize the soil by using fish buried with the seed to encourage growth. The seeds that were planted were winter squash, maize and climbing beans or as it is more commonly known the 3 sisters of agriculture.

Squanto also taught the colonists to catch eels and other fish. I can't speculate whether the colonists wouldn't have made it without the native Americans but I think they could have at least foraged the land come springtime. On a side note they certainly had an easier time getting established with the help of the native Americans in the area.

Rothbard, Murray Rothbard (1975). ""The Founding of Plymouth Colony"". Conceived in Liberty 1. Arlington House Publishers

Mt. Pleasant, Jane (2006). "38". In John E. Staller, Robert H. Tykot, and Bruce F. Benz. The science behind the Three Sisters mound system: An agronomic assessment of an indigenous agricultural system in the northeast. Histories of Maize: Multidisciplinary approaches to the prehistory, linguistics, biogeography, domestication, and evolution of maize. Amsterdam: Academic Press. pp. 529–537.