These were all the illustrations for Comic Art in America, a 1959 book by Stephen Becker about the medium up to that time.
The last strip in the chapter The Beginnings of a Big Business. As per the accompanying caption:
One of RUBE GOLDBERG's famous Foolish Questions, with the old sports cartoonist showing through.
The Gumps, 1935, by SIDNEY SMITH. The horizontal line near the bottom was for the benefit of newspapers—even then—which economized on space by trimming their strips.
Another Gumps of 1935. The preoccupation with lost financial opportunities is typical of Andy.
The first Gasoline Alley, a classic panel, dated August 14, 1919. Walt Wallet is instantly recognizable.
Frank King's Skeezix in a typical scene of army life—griping and deploring officers. 1942.
More army life by FRANK KING. These strips were authentic; what Skeezix went through, we all went through. 1943.
Little Orphan Annie, full of good drawing, suspense, and pathos. Switching from Annie to Daddy Warbucks and back again is highly effective; conceiving and laying out such a Sunday page is no easy task. 1956.
Harold Teen. This strip is dated 1951, and there are Harold and Shadow at the same old soda fountain, still dreaming.
FRANK WILLARD's beautiful slapstick in a Moon Mullins of 1941. Emmy, as usual, bears the brunt.
WALTER BERNDT's Smitty. Adults underestimate Smitty, who often makes exactly the same mistake with little brother Herby. 1952.
Reg'lar Fellers, with Jimmy Dugan, Puddn'head, and Pinhead.
Just Kids, in 1931. Mush Stebbins and Ignatius Conway were often at sword's point.
PERCY CROSBY's war sketches. 1918.
Skippy, by PERCY CROSBY in 1925.