Born in Lisbon into a converso family, he moved to British America, settling in the colony of Rhode Island and Providence Plantations.

[3] Aaron's older brother José had left Portugal years earlier, began to openly practise Judaism, and changed his given name to Moses.

[1] Moses was naturalized in 1740 and granted a license by the General Assembly to make potash in 1753, and he became a successful merchant in Newport.

[6] One of Lopez's early business interests was the trade in spermaceti, a coveted wax extracted from whale oil used to make elegant candles.

Whalers couldn't supply the factories with enough spermaceti to meet the demand, and the price of whale oil was climbing.

In 1761, Lopez joined eight other merchants to form a trust to control the cost and distribution of whale oil.

[11] By the beginning of the American Revolution, Lopez owned or controlled 30 vessels, engaged in the European and West Indian trade and in whale fisheries.

In October 1775, a Royal Navy force anchored outside Newport's harbour and the population began to evacuate the city.

In early 1776 Lopez relocated to Portsmouth, Rhode Island, then to Providence, Boston, and finally to Leicester, Massachusetts.

[2] Under the Naturalization Act 1740, any foreign Protestant who had resided in Britain's American colonies for seven years could become a British subject; while Catholics were excluded by the law, special provisions were allowed for the religious scruples of both Quakers and Jews.

Although he met the conditions set by law, Lopez's request was denied by the colonial government of Rhode Island.

The lower house approved their request and required that the men return to the Superior Court to take an oath of allegiance, but the terms of their citizenship would be limited: Jews could become citizens of Rhode Island, but they would not be allowed to vote or serve in public office.