I suppose very few people are interested in Lyndon Johnson these days, and why not? he passed out of history 40 years ago.
But if you have any interest in the United States this book is an absolute must. Caro writes with the wonderful fluency of a journaalist and tells the story, not just of Johnson, but of America in the 20th century. The story goes from the Comanche raids in Texas to the moon landings, taking in Civil Rights, which Johnson delivered where Kennedy could't, and Vietnam.
I've read all 3 volumes and can't wait for the final one on his Presidency. Fabulous, fabulous narrative writing.