It's idiomatic. Museum carries different expectations around the article compared to, say, university.
For example, when using university names of the form X University, the article is usually omitted. For instance, the set of Ivy League universities follows this convention:
Harvard University
Brown University
Columbia University
Cornell University
Princeton University
Yale University
One might refer to an object or entity associated with the university using an article (The Harvard University Register, The Harvard University Band), but it would be immediately conspicuous to say the Harvard University and not follow up with another noun phrase (even common ones like crew team or grounds). It's idiomatic.
Museums are different. Museums very often carry an article in their title when called X Museum. For instance, and off the top of my head:
The Victoria and Albert Museum (or the V&A)
The Metropolitan Museum of Art (or the Met)
The J. Paul Getty Museum (or the Getty)
The British Museum
In other words, museum has a stronger tendency to adopt the article the even when headed by a name. This is also idiomatic.
>to indicate a quote. – Andrew Leach Feb 04 '22 at 16:56