The specific cause of Parkinsonâs is unknown; however, medical experts believe the symptoms are related to a chemical imbalance in the brain caused by brain-cell death. Parkinson's disease is chronic (persists over a long period of time), and progressive (symptoms grow worse over time).arkinson's disease (or, simply, Parkinson's or PD) is the most common form of parkinsonism, a group of motor system disorders.
Quick Answer. Non-mandatory ZIP codes were introduced to the United States in 1963. Robert Moon, a postal inspector with the United States Postal Service, proposed the ZIP code system as early as 1944. Continue Reading.
Follow @TIME. 1963 was a momentous year in America: President John F. Kennedy was assassinated, Martin Luther King Jr. delivered his âI Have a Dreamâ speech at the March on Washington and, somewhat less heralded by all but the most fervent postal historians, the ZIP code was introduced.