Most likely, I think, mainstay salads Cobb and Caesar started the slow and steady evolution from California to the national home table.
It’s easy to remember Cobb salad’s ingredients by using the mnemonic EAT COBB: Egg (hard boiled), Avocado (sliced), Tomato (chopped), Chicken (boiled, baked or grilled but never fried), Onion, (chives), Bacon (very crisp and crumbled), Blue cheese (originally Roquefort) — then add lettuce (usually chopped romaine, iceberg, chopped watercress and/or endive) and red-wine vinaigrette. Some add black olives and take a few other liberties. It originated at the Hollywood Brown Derby restaurant, and is named for owner Robert Cobb. Whether developed by him or his chef around 1930 is debatable.
Caesar salad, developed in Santa Monica by chef-owner Caesar Cardini of Cardini’s Restaurant, is romaine lettuce (torn), croutons, Parmesan cheese, a salad dressing of lemon juice, olive oil, Worcestershire sauce, garlic and black pepper, with a coddled (lightly cooked) egg added before the salad is served at the table. There are plenty of optional ingredients now added, from anchovies (which are in the Worcestershire sauce already) to a choice of protein.