Classified boards are not an endangered species. They are hiding in plain sight among firms not covered in commercial databases, typically those in the S&P 1500 Index. We utilize machine learning algorithms to determine the classified board status for all U.S. public firms and show that between 1996 and 2020, the fraction of firms in the S&P 1500 with a classified board fell from 58% to 29%. Conversely, this fraction for non-S&P 1500 firms increased from 39% to 50% over the same period. This difference in trends remains when we control for firm characteristics, such as age and size, or exploit only within-firm variation. We find a substantial increase in attention to governance and classified boards over time and a sharp increase in passive ownership of S&P 1500 firms, suggesting that the visibility of being in the S&P 1500 Index creates pressure from market participants, especially passive investors that cannot vote with their feet, to declassify the firm’s board. Consistent with this notion, S&P 1500 firms are over five times more likely than non-S&P 1500 firms to vote on board declassification in a given year. We also use our expanded dataset to reexamine prior findings on classified boards and show that some conclusions are significantly changed when focusing on firms outside the S&P 1500.