How much progress was made towards freedom, equality, and opportunity for homosexuals in the mid-1970s?
There was not very much progress at all made towards equal rights for homosexuals during the mid 1970s. The major goals of the gay rights movement remained unachieved until at least the turn of the century and many of them have still not been achieved today.
During the 1970s, gay rights activists were mainly pushing for two main things. They wanted laws that would protect them from discrimination on the basis of sexual orientation. That is, they wanted laws that would make it illegal to do things like firing someone because they were gay. They also wanted an end to laws that made homosexual conduct illegal. They did not achieve either of these.
For example, gay rights advocates did manage to get an anti-discrimination law passed in Dade County, Florida. But a backlash arose and roughly 70% of voters voted to repeal the law. It was not until 1982 that a state passed an anti-discrimination law. Many states still do not have them and neither does the federal government.
As to laws banning homosexual conduct, these laws remained on the books until 2003. In 1986, such laws were upheld by the Supreme Court in Bowers v. Hardwick. It was not until the 2003 case of Lawrence v. Texas that such laws were ruled to be unconstitutional.
Gay rights advocates made very little progress in the 1970s. They did not gain any real legal victories and they did not achieve much in the way of social acceptance either.