Letter from Rebbe Yosef Yitzchak Schneersohn, the Rayatz of Lubavitch. Brooklyn NY, 24th Sivan 1940.
Typewritten on the rebbe's official stationery, with his signature "Yosef Yitzchak" (the letter was written shortly after the rebbe reached the United States, during his temporary stay at the Greystone hotel in Manhattan, before he settled at 770. The letterhead is therefore not the usual one with the address of the Chabad headquarters at 770, rather bears an inkstamp with the address of the president of Agudas Chassidei Chabad, R. Yisrael Jacobson).
Addressed to his relative R. Azriel Zelig Slonim, shortly after his return to Jerusalem from his mission in Australia. The rebbe writes that he will try to help him find a source of livelihood, and blesses him with abundant sustenance, so that he can apply himself to Torah study and worship of G-d.
Further in the letter, the rebbe extends many poetic blessings to his Chassidim.
R. Azriel Zelig Slonim (1897-1971), a leading Chabad activist, member of Agudas Chassidei Chabad and director of Kollel Chabad. He was one of the founders of Irgun N'shei UBnos Chabad and the Beit Chanah institutions, and helped establish Shikun Chabad in Jerusalem.

[1] leaf, official stationery. Approx. 28 cm. Good condition. Filing holes. Folding marks. Stains and minor wear. Minor marginal tears.