Before slipping away quietly, Umar ibn al-Khattab first made his Hijrah a matter of open defiance: he armed himself, went to the Ka'bah, performed tawaf seven times, and announced to the assembled Quraysh that he was leaving for Madinah and that anyone who wished to make his mother childless, his children orphans, or his wife a widow could meet him outside the city, and no one took up the challenge. He then arranged to emigrate together with Hisham ibn al-As and Ayyash ibn Abi Rabi'ah, agreeing to meet at a valley outside Makkah at dawn on an appointed day, with anyone who failed to arrive assumed to have been prevented by circumstances. Hisham did not arrive in time, so Umar and Ayyash emigrated without him and reached Madinah safely.
Umar RA's public, unashamed Hijrah, announced at the Ka'bah after arming himself and daring any of the Quraysh to stop him, stood as a singular act of open defiance; per Ali ibn Abi Talib, no one else performed the Hijrah so openly, and no one took up Umar RA's challenge.
Other events recorded in 1 BH. Their order within the year is not established; use the storyline above for the sequence.
O people of Makkah! Whoever wishes that his mother lose him tonight, or that his children become orphans, or his wife a widow, then know that I am performing the Hijrah, and you can meet me outside of Makkah in such-and-such a valley.
Announced after arming himself and performing tawaf around the Ka'bah seven times.
I don't know of anyone who did the Hijrah publicly except for Umar. He was the only one to do it publicly.