Click on a circle in the chart to view Sham immigration records. You can find out when most of the Sham families immigrated to the United States. You can focus your search to immigration records dating from that era. Immigration records can tell you an ancestor's name, ship name, port of departure, port of arrival and destination.
Probably, however...: As my colleague dr. Pappas mentions, marijuana is almost always tested in urine rather than blood, so someone would almost certainly pass a blood test but is more likely to face a urine test.
How does hydrocodone affect the blood? Can blood tests detect high blood pressure? How long of a period of abstinence from marijuana is required to pass a blood/urine test? How long is alcohol detected in stored blood? Will metformin be detected in blood test during drug detection?