Before we usher in the new year, it’s time for a retrospective of 2015.Here’s our roundup of some of the biggest stories across the country, events that influenced national conversations on issues from police brutality to gay marriage, tragedies that shook our psyche and acts of heroism that showed Americans at their best. Alabama: Despite U.S. ruling legalizing gay marriage, gay adoption still a battle in the statesIt’s a story chock-full of contention. Two lesbian mothers fight for custody of their three children. Two state courts are at odds over adoption rights for same-sex couples — or at least until the Supreme Court stepped in. But first, some background: When the women — identified only as “E.L.” and “V.L.” in court documents — were still together, they temporarily moved to Georgia to sidestep Alabama law, which wouldn’t allow V.L. to legally adopt the children (E.L. was their birth mother). Georgia, on the other hand, was fine with it. But when the couple split up, things got messy. E.L. decided Alabama had the right idea after all and denied V.L. parental rights. And V.L. wasn’t having it. She took things all the way up to the Supreme Court, which blocked Alabama’s ruling on Dec. 14. If you need an explainer (we bet you…