Restoring tabs in Chrome

I've long had a lot of tabs open in Chrome. When I reboot, it either opens them or asks if I want to restore.

Yesterday, I bumped a key that sort of maximized the browser and had a white screen. It wouldn't undo it, eventually I rebooted. It came up again, saying it's unresponsive.

I closed Chrome and re-opened it and now it doesn't have the old tabs. If I look in history, it lists them, but won't offer to make them active again.

How can I get it to make the tabs in history active again?