I work in IT at a university. There is a state parental leave program, but above that the union bargained for additional parental leave.
The US has a significant separation between the federal and state levels. For a policy like this, you usually would find some of the more progressive states trying out different programs. Some more backward states will take a long time to come round. It really is more like a bunch of small to medium sized countries in that respect.
Russia is also working under very different demographics, which is probably driving at least the maternity leave. Birth rates are low and net migration, while positive, is not enough to keep up. The US has a birth rate that is closer to replacement and much higher net migration. That would mean lagging states would have less pressure to reform.