April 1. On this date in 1916, 'Abdu'l-Bahá wrote his "Tablet to the Bahá’ís of the Western States," which is the 4th part of his "Tablets of the Divine Plan," in 'Abdu'l‑Bahá’s room at the mansion of Bahjí, and addressed to the Bahá’ís of eleven Western States of the United States.

April 1. On this date in 1916, 'Abdu'l-Bahá wrote his Tablet to the Bahá’ís of the Western States, which is the 4th part of his Tablets of the Divine Plan, in 'Abdu'l‑Bahá’s room at the mansion of Bahjí, and addressed to the Bahá’ís of eleven Western States of the United States: New Mexico, Colorado, Arizona, Nevada, California, Wyoming, Utah, Montana, Idaho, Oregon and Washington. Included in multiple books, the first five tablets were printed in America in Star of the West - Vol. VII, No. 10, September 8, 1916, and all the tablets again after World War I in Vol. IX, No. 14, November 23, 1918.

On December 23, 1918, 'Abdu'l-Bahá sent his secretary Ahmad Sohrab to the United States to personally deliver the Tablets of the Divine Plan. These collective letters, along with Bahá’u’lláh’s Tablet of Carmel and ‘Abdu’l-Bahá's Will and Testament were described by Shoghi Effendi as "three of the Charters" of the Bahá’í Faith, which along with the Kitáb-i-Aqdas (which Shoghi Effendi described as "the basic laws and ordinances on which the fabric of His future World Order must rest") set the foundation of the Administrative Order. Ahmad Sohrab would later be declared a Covenant-breaker by Shoghi Effendi.

He is God!
O ye sons and daughters of the Kingdom:
DAY and night I have no other occupation than the remembrance of the friends, praying from the depth of my heart in their behalf, begging for them confirmation from the Kingdom of God and supplicating the direct effect of the breaths of the Holy Spirit. I am hopeful from the favors of His Highness the Lord of Bestowals, that the friends of God during such a time may become the secret cause of the illumination of the hearts of humanity, breathing the breath of life upon the spirits—whose praiseworthy results may become conducive to the glory and exaltation of humankind throughout all eternity. Although in some of the Western States, like California, Oregon, Washington and Colorado, the fragrances of holiness are diffused, numerous souls have taken a share and a portion from the fountain of everlasting life, they have obtained heavenly benediction, have drunk an overflowing cup from the wine of the love of God and have hearkened to the melody of the Supreme Concourse—yet in the states of New Mexico, Wyoming, Montana, Idaho, Utah, Arizona and Nevada, the lamp of the love of God is not ignited in a befitting and behooving manner, and the call of the Kingdom of God has not been raised. Now, if it is possible, show ye an effort in this direction. Either travel yourselves, personally, throughout those states or choose others and send them, so that they may teach the souls. For the present those states are like unto dead bodies: they must breathe into them the breath of life and bestow upon them a heavenly spirit. Like unto the stars they must shine in that horizon and thus the rays of the Sun of Reality may also illumine those states.
God says in the great Qur’án: “Verily God is the helper of those who have believed. He will lead them from darkness into light.” 1 This means: God loves the believers, consequently He will deliver them from darkness and bring them into the world of light. It is also recorded in the blessed Gospel: Travel ye throughout the world and call ye the people to the Kingdom of God. 2 Now this is the time that you may arise and perform this most great service and become the cause of the guidance of innumerable souls. Thus through this superhuman service the rays of peace and conciliation may illumine and enlighten all the regions and the world of humanity may find peace and composure.
During my stay in America I cried out in every meeting and summoned the people to the propagation of the ideals of universal peace. I said plainly that the continent of Europe had become like unto an arsenal and its conflagration was dependent upon one spark, and that in the coming years, or within two years, all that which is recorded in the Revelation of John and the Book of Daniel would become fulfilled and come to pass. This matter, in all probability, was published in the San Francisco Bulletin, October 12, 1912. You may refer to it, so that the truth may become clear and manifest; thus ye may fully realize that this is the time for the diffusion of the fragrances.
The magnanimity of man must be heavenly or, in other words, it must be assisted by the divine confirmation, so that he may become the cause of the illumination of the world of humanity.
Upon you be greeting and praise!

1. Qur’án 2:257.
2. Cf. Mark 16:15.