Prison camps sprang up all along the projected canal route in the summer of 1949 and were quickly filled with political prisoners brought from jails from throughout the country. These first arrivals were soon joined by newly arrested people who were sent to the canal in ever increasing numbers. By 1950 the forced labor camps set up along the length of the planned canal were filled to capacity; that year alone, up to 15,000 prisoners were held in those camps. By 1953, the number of prisoners had swelled to 20,193, though older estimates claimed figures as high as 60,000 (other estimates asserted 100,000 or 40,000 for the entire period). British historian and New York University professor Tony Judt claimed in his book, "Postwar: A History of Europe Since 1945", that, overall, one million Romanians had been imprisoned in various prisons and labor camps, including those on the path of the canal.