What caused American colonists in different states to unify as one nation leading up to the French and Indian War?

Many different factors led to a highly evolved sense of unity and identity among the colonists. War and British negligence and victimization resulted mainly in colonial unification, while diversity and the distance between Europe and North America resulted in a distinctively American identity.

it is a part of john locke's natural rights popular during the age of enlightenment that people had inalienable rights to life, liberty and property. this was reflected by thomas jefferson in his declaration of independence as rights to life,liberty and the pursuit of happiness.

another line in the declaration of independence is that people have certain rights just because they are human. humans are capable of obeying the three natural rights john locke mentioned making them governable by these laws and therefore entitled to these rights as well.