The founders were not close to liberalism.
They opposed government controlling every aspect of your daily life.
They opposed career politicians.
They opposed lobbyists.
They believed in states rights.
They believed in limited government.
They believed in people doing for themselves.
They believed in the US having a military
They believed in property ownership
Then indeed the Framers were liberal, as liberals support the above as well.
More importantly, liberals support and understand the above in their appropriate Constitutional and legal context, as intended by the Framers.
For example, liberals oppose government controlling every aspect of ones daily life, particularly with regard to privacy rights, due process rights, and equal protection rights. Liberals also correctly understand, as did the Framers, that although inalienable, rights are not absolute, and are subject to appropriate, reasonable government restrictions.
Liberals support states rights, and as did the Framers correctly understand that Federal laws, the Federal Constitution, and rulings by Federal courts are supreme, where the states do not have the right to ignore or nullify. Federal laws.
Liberals believe very much in limited government, where government lacks the authority to dictate to a woman whether she may have a child or not, lacks the authority to deny same-sex couples access to marriage, lacks the authority to deny immigrants their due process rights, lacks the authority to compel public assistance applicants to take drug tests, and where government lacks the authority to place undue burdens to the right to vote.
In fact, since the Foundation Era, liberals have been at the forefront of championing limited government and enhancing the civil liberties of all persons.
And Liberals believe in individualism, the military, and private property ownership just as did the Framers, who, again, were clearly liberal.