The British pound sterling is the oldest currency still in use today. It has been around in various forms for over 1,200 years. The US dollar became the dominant global reserve currency after World War II. Together, these two currencies make up one of the most liquid trading pairs in foreign exchange markets.
The pound hit an all-time low against the dollar in 1985 when it briefly traded near 1.05. It recovered strongly in subsequent years and was worth over 2.00 dollars in 2007 before the financial crisis pulled it back down. More recently, the Brexit vote in 2016 caused a sharp drop in the pound, and it has traded in a lower range since.
For Americans visiting the United Kingdom, the exchange rate determines how far your dollars stretch. A weaker pound means your dollars buy more in the UK. For British businesses buying American goods, a stronger pound means lower costs.