On this day in 5700/1940, the official “closing” on the building of 770 took place.
Soon after the Frierdiker Rebbe arrived on 9 Adar II of that year, a special Vaad headed by Rav Shlomo Aron Kazarnovsky began to look for a suitable place for the Rebbe to live and to have his court. After a while, the building of 770 was found to be a suitable place, with room for an apartment, yechidus room, offices for the mosdos, and a shul.
After initial opposition from neighbors, the Vaad purchased the house on 12 Menachem Av, 5700/1940.
(The purchase was made for $30,000. After inflation, that would be $525,000 in today’s money.)