In the 19th century, the British colonial administration in India established a massive internal customs line, known as the Inland Customs Line, stretching about 4,030 kilometers from the Himalayas to Orissa. This system was designed to control and tax the movement of goods within the region, particularly salt, which was a vital commodity. A unique feature of this line was a living barrier made of thorny plants, spanning at least 1,300 kilometers. The hedge was constructed using species like jujube, acacia, karonda, prickly pear fig, and euphorbias, creating a dense, natural wall that was difficult to cross. According to reports from the commissioner of internal customs, as cited by researcher Roy Moxham, the hedge varied in size, reaching heights of up to 3.7 meters and thicknesses of 4.3 meters in some areas. Maintaining this structure required a significant workforce—14,188 men in 1872, averaging more than three men per kilometer. The system was eventually abolished in 1879 after financial reforms standardized taxes across India, reducing the need for strict customs enforcement and making salt smuggling less necessary. Despite the abolition, the hedge may have remained intact for a decade, as no one had an incentive to maintain it once the posts were closed. Over time, parts of the hedge were likely repurposed for roads and railways, erasing much of its original form. In 1995, Roy Moxham, then a curator at the University of London's library, uncovered a reference to the hedge in the memoirs of British official William Henry Sleeman. After extensive research, Moxham identified a small elevated embankment in the Etawah district of Uttar Pradesh in 1998, which may be the last remaining trace of the "Great Hedge of India." Today, the hedge itself has largely disappeared, with only a faint elevated strip of earth remaining near cultivated fields. The salt tax, which was a key factor in the hedge's creation, continued to exist and later played a significant role in Mahatma Gandhi's Salt March, a pivotal moment in India's independence movement. Moxham's research on this historical structure was published in 2001 in a book titled The Great Hedge of India, published by Constable & Robinson.