Adams's prediction was off by two days. From the outset, Americans celebrated independence on July 4, the date shown on the much-publicized Declaration of Independence, rather than on July 2, the date the resolution of independence was approved in a closed session of Congress.
LSD effects usually last for 12 hours. But LSD can stay in your system for up to 5 days after use. More on the bioavailability, half life and detection window
Effects of LSD Use. The effects of LSD are unpredictable. Usually, the first effects of the drug are felt 30 to 90 minutes after taking it. The user may experience extreme changes in mood, feel several different emotions at once, or swing rapidly from one emotion to another.