The Humane Society of the United States is a great organization.
I agree, I appreciate them for their work in the fight agains factory farming, animal fighting, puppy mills and the like.
Do you know when it was founded?
It was founded in 1954 in Washington DC. The ones that founded it were former members of the American Humane Society.
Wow!    Are they associated with any other organizations?
They aren't associated with any local humane societies or any other animal organizations. You would think they would be, but they're independent of any.
How do they raise their funding?
They operate entirely by private membership dues, grants and donations. People have generously given their money to this organization simply out of respect for animal welfare.
That is quite generous!
I completely agree. They were identified in 2013 as the 136th largest charity in the United States. That is saying something with regards to their caring for animals.