The Civil War did prevent the construction of modern infrastructure in the South, but it was not the only factor, and the quote seems to imply that the South was on its way when the Civil War hit and ended their efforts. But it's more complicated than that. In the antebellum, the Democratic-dominated South opposed efforts in favor of internal improvements (read, building infrastructure) at the national level. In fact, a quick trip to Wikipedia will show you many Democratic presidents vetoing infrastructure projects because they believe it's unconstitutional. The Republicans, a thoroughly Northern party (to the extent that Lincoln did not even appear in the ballot of most Southern states) and descendants of the Whigs, supported internal improvements, and it was the South's secession that allowed a Republican president and a Republican Congress to approve massive infrastructure programs like the transcontinental railroad.

So, it was not the North that prevented the South from building infrastructure. The South itself was not interested in infrastructure programs headed by the Federal government, and State governments usually limited themselves to a "colonial" pattern of infrastructure - that is, railroads that unite the regions that produce cash crops such as cotton or sugar with the ports that allow them to be exported. With a lower, less urban population than the North, the South had no real reason to invest in a massive program of infrastructure, especially because such industrial expansion would threaten the dominant planter class. State governments did invest in the construction of railroads; in fact, Georgia's government used slaves to build one. But the ventures were small and lacked capital because, again, "their primary purpose [was] to transport plantation staples to the coast."

Only a small band of modernizers challenged this, and instead urged the South to modernize and enter the industrial revolution the North was already going through. As in other ante-bellum ventures, sectionalism motivated in part this desire, for Southerners were extremely worried about the data that showed that they lagged behind the North in population, economy, and railroad mileage. “Our whole commerce except a small fraction is in the hands of Northern men," denounced an Alabamian, calling it a “degrading vassalage” that meant that “financially, we are more enslaved than our Negroes.” In proposing a vigorous program of industrial expansion that had the railroad as one of its cornerstones, Southern modernizers hoped to break from the North and be able to sustain themselves.

DeBow's review, a popular New Orleans newspaper, thus took the lead in organizing Conventions to discuss the best means to industrialize the South and calling for action "in the busy hum of mechanism, and in the thrifty operations of the hammer and anvil." But, despite abundant room for the expansion of railroads and textile industries, these modernizing efforts failed miserably. It's true that Southern railroad mileage grew by a factor of four, compared with its growth by a factor of three in the North, and that investment in industry did increase. But the North was so far ahead that the South's share of the national industry actually decreased by 16%.

The Civil War, of course, did not help. The South had much less railroad mileage than the North, and thus its logistical capacity was strained by the needs of its armies. Moreover, when parts or engines broke down, the South was unable to produce the necessary replacements. Southern railways quickly deteriorated, and that contributed to the problems of logistics that plagued the Southern war effort, especially when it comes to foodstuffs. Since there was no way to transport food or supplies, civilians and soldiers suffered hunger while abundant grain rotted in far away barns. Yankee raiders and soldiers also destroyed the railroads that came under their control, as a way to further damage the Confederate cause. Sherman, for example, famously made "neckties" with the railroads of Georgia. When the Confederacy finally collapsed, Southern infrastructure was in a sorry state of disrepair.

During Reconstruction, both the governments of Presidential Reconstruction and Radical Reconstruction attempted to repair and extend the infrastructure of the South. Since infrastructure was mostly seen as falling under the purview of state governments, the Federal government for the most part did not head efforts to expand Southern infrastructure itself. The heavyweighting fell on the shoulders of the new state governments, which during Presidential Reconstruction was mostly in the hands of former Whigs friendly to internal improvements. A "railroad fever" swept the region, and states happily extended credit to railroad enterprises and took measures in the hopes of attracting Northern capital. Nonetheless, as Foner writes, "The programs of railroad aid accomplished virtually nothing." Other efforts to attract investment and industry failed similarly.

The disastrous economic effects of the Civil War and lingering influence from planters opposed to internal improvements help explain this failure, alongside with the instability of the South's politics. Foner argues that the fact that the South had been and still was a plantation society also explains this backwardness, because these societies "have weak internal markets, and planter classes use their political power to prevent the emergence of alternative economic enterprises that might threaten their control of the labor force." Consequently, during Presidential Reconstruction Southerners did not take other steps necessary for true industrial development, because they clashed with their attempt to reestablish their plantation economy. For example, they made laws that kept blacks down, thus preventing the formation of a true free labor system, and saw railroads as mostly a means to reinvigorate the plantation rather than connect the country.

The governments of Radical Reconstruction did not have much success either. The great majority of Southern Republicans were strong supporters of railroad expansion as a way of modernizing the South. Thus, they supported the "Gospel of Prosperity" that promised to bring industry and infrastructure to the South, legitimacy to the new governments, and jobs for the freedmen. Naturally, Republicans also had the replacement of a plantation economy with a free labor one as one of their objectives, and they accepted the full implications of industrial change. In this, they were radically different from their predecessors, both from the antebellum and Presidential Reconstruction. To achieve this, Republican governments offered credit and economic aid, chartered corporations, and even bought stock directly. Of course, they also tooks measures to attract Northern investment.

But, "the program of state-sponsored capitalist development, inaugurated with grandiose hopes, proved in many ways the party’s undoing." Taxes and debts skyrocketed, undermining the Republicans' support, and the program offered ample opportunities for corruption, which allowed Democratic opponents to paint the Reconstruction governments as corrupt and inefficient. Upcountry scalawags, the base of the white support that they desperately needed, were alienated by these efforts, which they saw as needless intrusion that threatened to slave them to the needs of the free market. Bonds flooded the market, and their value quickly decreased. Though 3,300 miles of railroad track were laid, an increase of 40%, this growth was limited, and by the early 1870's the program had to be stopped as the governments tethered in the edge of bankruptcy, unable to meet the extravagant obligations they had acquired.

At the Federal level, as I already said, there were few efforts for a massive expansion of Southern infrastructure. Republicans were friendly to internal improvements, and Northern Republican governments readily expanded infrastructure and industry. But, with the waning of Radicalism and a retreat from the idea of a powerful National governments, the Republican Congress was unwilling to undertake programs for building infrastructure directly or set Federal funds for investment in the South. The South's weak economy and political troubles only reinforced Federal reluctance. For example, a Mississippi Republican said that his bill for improvements in the Yazoo river would only be passed if it “be considered as lying within the boundaries of Wisconsin and Michigan,” Rather than some Northern conspiracy to hold the South down, you must remember that the government as a whole still considered infrastructure to be a state matter, with the exception of projects over the territories, ports or rivers, and its main way of encouraging infrastructure was through land grants.

Redeemer governments that came into power after the end of Reconstruction did not have a coherent economic plan - Tennessee dismantled the Republican railroad program, but Virginia continued to grant "enormous concessions" to railroad companies. In the Deep South, the Panic of 1873 that helped to unravel Reconstruction ironically helped along in the development of Southern infrastructure, for Northern investors were able to buy and consolidate the rails. Nonetheless, all programs for infrastructure expansion failed, and at the end "the South’s share of national track mileage fell by 20 percent during the 1870s." When Reconstruction finally ended, the new governments for the most part prohibited aid to railroads and returned to a "colonial mold" - producing raw material for Northern factories.