When Michael Heller proposed that excessively fragmented property rights in land can frustrate its commercial development, patent scholars began debating whether Heller’s anticommons theory applies to property rights in inventions. Do “patent thickets” exist? The rise and fall of the first American patent thicket—the Sewing Machine War of the 1850s—confirms that patent thickets do exist and that they can frustrate commercial development of new products. But this historical patent thicket also challenges the widely held assumption that this is a modern problem arising from allegedly new issues in the patent system, such as incremental high-tech innovation and the impact of “patent trolls.” The Sewing Machine War exhibited all of these phenomena, proving that these are hoary issues in patent law. The denouement of this patent thicket in the Sewing Machine Combination of 1856, the first privately formed patent pool, further challenges the conventional wisdom that patent thickets are best solved through public-ordering regimes that limit property rights in patents. The invention and incredible commercial success of the sewing machine is a striking account of early American technological, commercial, and legal ingenuity, which heralds important empirical lessons for how patent thicket theory is understood and applied today.