Several important United States services closed on Wednesday, including the U.S. Postal Service. Those with an avid interest in following the stock market may have also noticed the closure of the New York Stock Exchange, the Nasdaq and all other indexes. This is because of Wednesday’s national day of mourning for former President George Herbert Walker Bush.

It is customary for state services to shut down as the nation mourns former presidents, and that includes the stock market. The stock market also shut down following the deaths of Richard Nixon in 1994, Ronald Reagan in 2004 and Gerald Ford in 2007.

The 41st President of the U.S. died Saturday at the age of 94. President Donald Trump, first lady Melania Trump and other former presidents and vice presidents were in attendance at Bush’s funeral.

The memorial service for Bush will last until Thursday and much of it can be seen on C-SPAN.