I'm not history-buff, but I found this on Wikipedia: In 1873 the city council of Paris voted a law of public utility to seize land at the summit of Montmartre for the construction of the basilica. Architect Paul Abadie designed the basilica after winning a competition over 77 other architects. With delays in assembling the property, the foundation stone was finally laid 16 June 1875. Passionate debates concerning the Basilica were raised in the Conseil Municipal in 1880, where the Basilica was called "an incessant provocation to civil war" and it was debated whether to rescind the law of 1873 granting property rights, an impracticable proposition. The matter reached the Chamber of Deputies in the summer of 1882, the Basilica being ably defended by Archbishop Guibert and Georges Clemenceau expressing the view that the Basilica sought to stigmatise the Revolution. The law was rescinded, but the Basilica was saved by a technicality and was not reintroduced in the next session. A further attempt to halt the construction was defeated in 1897, by which time the interior was substantially complete and had been open for services since 1891.

I loved your history lesson on the basilica.. If you have not seen it, I hope you have a chance to one day.. It is truly beautiful.