For those of us who were engrossed in Ken Burns’ latest film, this is the “week without Roosevelts.” Last week I could come home from the workaday world of the 21st century and enter, for two hours, the 19th and 20th. The latter half of the show was recent history for me, times that my parents and grandparents lived through, and times, therefore, that I don’t always consider history.

But it is history, and well worth learning. The film left me with curiosity — wanting to read books about TR, FDR and ER — and with hard-to-forget images: a diagram of where the bullet struck Teddy Roosevelt as he was giving a campaign speech. (He spoke for another hour before going to the hospital.) Photographs of ordinary Americans, their heads inclined toward big boxy radios, listening to FDR’s fireside chats.

On those nights, apparently, you could leave your house, walk down the street and never stop listening to the president’s voice. FDR’s words, calm and comforting, were pouring out of every window, were soothing the jangled nerves of a troubled nation.

Would we ever again be so unified? Maybe on September 12, 2001. But then again, maybe not.