Steve Trevor died at the end of Wonder Woman after sacrificing himself to ensure that a plane full of deadly gas couldn’t harm anyone on the ground. Is this Steve Trevor the same Steve Trevor that we saw in Wonder Woman who was transported to 1984 because of something like time travel, a descendant of Steve Trevor’s who is also named Steve Trevor (and looks exactly like Pine), a clone, or something else entirely? (It’s a comic book movie, so anything is possible.)
Diana was born circa 5000 years ago on the newly-created island of Themyscira to Zeus and Hippolyta, the Queen of the Amazons, mere months after the War of the Gods. Zeus intended for the child to one day grow strong enough to defeat Ares, the God of War. Fearful for her daughter's safety, Hippolyta lied to Diana about her true parentage, instead telling Diana that she'd sculpted her from clay and prayed to Zeus to bring her to life. Diana would believe this story for most of her life.
In one episode, a newspaper editor named Brown, desperate to discover Wonder Woman’s past, assigns a team of reporters to chase her down; she easily escapes them. Brown, gone half mad, is committed to a hospital. Wonder Woman disguises herself as a nurse and brings him a scroll. “This parchment seems to be the history of that girl you call ‘Wonder Woman’!” she tells him. “A strange, veiled woman left it with me.” Brown leaps out of bed and races back to the city desk, where he cries out, parchment in hand, “Stop the presses! I’ve got the history of Wonder Woman!” But Wonder Woman’s secret history isn’t written on parchment. Instead, it lies buried in boxes and cabinets and drawers, in thousands of documents, housed in libraries, archives and collections spread all over the United States, including the private papers of creator Marston—papers that, before I saw them, had never before been seen by anyone outside of Marston’s family.