A tiny, uninhabited Caribbean rock sparked a landmark Supreme Court case on American empire.

Countries & Cities · Published 30 September 2026 Swipe more like this →

In short: Navassa Island is a two-square-mile patch of limestone and bird droppings that became an unlikely flashpoint for U.S. expansion. Acquired under the 1856 Guano Islands Act, this desolate territory hosted a brutal mining operation that culminated in a violent revolt, a federal murder trial, and a pivotal Supreme Court ruling.

In the mid-19th century, guano was a prized commodity, essential for both fertilizer and the saltpeter needed for black powder. When American deposits neared exhaustion, Congress passed the Guano Islands Act of 1856, empowering citizens to claim unclaimed, guano-rich islands for the United States. Captain Peter Duncan claimed Navassa in 1857, and by 1865, the Navassa Phosphate Company had begun intensive mining operations. The island, characterized by sharp, 50-foot cliffs and a lack of natural water, was a harsh environment where laborers lived in grueling conditions.

The operation relied on roughly 150 workers, primarily recently emancipated Black men, who were subjected to abusive supervision. In 1889, tensions boiled over into a revolt that left three to five supervisors dead. The subsequent federal trial of 18 workers in Baltimore became a national sensation, raising complex questions about labor rights, the legacy of Reconstruction, and the reach of American jurisdiction. The defense challenged the legality of the U.S. claim to the island, leading to the 1890 Supreme Court case Jones v. United States, which affirmed the constitutionality of the Guano Islands Act.

Although the Supreme Court upheld the convictions, the case drew significant public outcry. Black churches and even the original jurors petitioned President Benjamin Harrison, citing the horrific treatment of the workers and their lack of legal protection. Harrison ultimately commuted the death sentences of three miners in 1891. Today, Navassa remains an unincorporated U.S. territory, though it is also claimed by Haiti, which has asserted sovereignty over the island in its constitutions since 1874. The island is now largely abandoned, serving as a quiet, wind-beaten reminder of an era when the United States scoured the globe for resources to fuel its growing industrial power.

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