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
After taking LSD, the effects -- known as a trip -- usually start within an hour and can last up to 12 hours, with a peak about halfway through the experience. Exactly how LSD affects each person varies widely. Some physical changes in the body during tripping include dilated pupils, increased blood pressure and a high body temperature. People on LSD may also feel dizzy, sweat, have blurred vision and feel tingling in their hands and feet. They may feel drowsy but not sleepy.