Here is the Washington Post review:

Of late we have been blissing out on books and other material about the Revolutionary period, and of course the Civil War years are of inexhaustible fascination to millions, but the years in between are pretty much ignored. Yet as Daniel Walker Howe makes plain in this exemplary addition to the Oxford History of the United States, this was the time when the United States was transformed by a series of revolutions, the most important of which were in transportation and communications, that "would overthrow the tyranny of distance," which until then had "remained for Americans 'the first enemy,' as it had been for inhabitants of the Mediterranean world of the sixteenth century."

...

"In a broader sense ... the spread of the electric telegraph effectively decoupled communication from transportation, sending a message from sending a physical object. The implications of this alteration in the human condition unfolded only gradually over the next several generations. But contemporaries fully realized that they stood in the presence of a far-reaching change. They valued not only the shortening of time to receive information but also the speed with which an answer could be returned; that is, conversation was possible.

Among a wealth of praise, "What Hath God Wrought" also earns a starred review from Publishers Weekly:

In the latest installment in the Oxford History of the United States series, historian Howe, professor emeritus at Oxford University and UCLA (The Political Culture of the American Whigs), stylishly narrates a crucial period in U.S. history—a time of territorial growth, religious revival, booming industrialization, a recalibrating of American democracy and the rise of nationalist sentiment. Smaller but no less important stories run through the account: New York's gradual emancipation of slaves; the growth of higher education; the rise of the temperance movement (all classes, even ministers, imbibed heavily, Howe says). Howe also charts developments in literature, focusing not just on Thoreau and Poe but on such forgotten writers as William Gilmore Simms of South Carolina, who helped create the romantic image of the Old South, but whose proslavery views eventually brought his work into disrepute. Howe dodges some of the shibboleths of historical literature, for example, refusing to describe these decades as representing a market revolution because a market economy already existed in 18th-century America. Supported by engaging prose, Howe's achievement will surely be seen as one of the most outstanding syntheses of U.S. history published this decade.