Background: Albert Sidney Johnston (February 2, 1803 - April 6, 1862) served as a general in three different armies: the Texian (i.e. Republic of Texas) Army, the United States Army, and the Confederate States Army. He saw extensive combat during his 34-year military career, fighting actions in the Black Hawk War, Texas War of Independence, the Mexican-American War, the Utah War, and the American Civil War. Considered by Confederate States President Jefferson Davis to be the finest general officer in the Confederacy before the later emergence of Robert E. Lee, he was killed early in the Civil War at the Battle of Shiloh on April 6, 1862.
Context: Johnston had various remaining military units scattered throughout his territory and retreating to the south to avoid being cut off. Johnston himself retreated with the force under his personal command, the Army of Central Kentucky, from the vicinity of Nashville. With Beauregard's help, Johnston decided to concentrate forces with those formerly under Polk and now already under Beauregard's command at the strategically located railroad crossroads of Corinth, Mississippi, which he reached by a circuitous route. Johnston kept the Union forces, now under the overall command of the ponderous Maj. Gen. Henry Halleck, confused and hesitant to move, allowing Johnston to reach his objective undetected. This delay allowed Jefferson Davis finally to send reinforcements from the garrisons of coastal cities and another highly rated but prickly general, Braxton Bragg, to help organize the western forces. Bragg at least calmed the nerves of Beauregard and Polk who had become agitated by their apparent dire situation in the face of numerically superior forces before the arrival of Johnston on March 24, 1862.  Johnston's army of 17,000 men gave the Confederates a combined force of about 40,000 to 44,669 men at Corinth. On March 29, 1862, Johnston officially took command of this combined force, which continued to use the Army of the Mississippi name under which it had been organized by Beauregard on March 5.  Johnston now planned to defeat the Union forces piecemeal before the various Union units in Kentucky and Tennessee under Grant with 40,000 men at nearby Pittsburg Landing, Tennessee, and the now Maj. Gen. Don Carlos Buell on his way from Nashville with 35,000 men, could unite against him. Johnston started his army in motion on April 3, 1862, intent on surprising Grant's force as soon as the next day, but they moved slowly due to their inexperience, bad roads and lack of adequate staff planning. Due to the delays, as well as several contacts with the enemy, Johnston's second in command, P. G. T. Beauregard, felt the element of surprise had been lost and recommended calling off the attack. Johnston decided to proceed as planned, stating "I would fight them if they were a million." His army was finally in position within a mile or two of Grant's force, and undetected, by the evening of April 5, 1862.
Question: What can you tell me about Concentration at Corinth?
Answer: Johnston had various remaining military units scattered throughout his territory and retreating to the south to avoid being cut off.

Background: Abu Bakr as-Siddiq 'Abdallah bin Abi Quhafah (Arabic: 'bw bkr lSdyq `bd llh bn 'by qHf@; c. 573 CE - 22 August 634 CE), popularly known as Abu Bakr ('bw bkr), was a senior companion (Sahabi) and--through his daughter Aisha--the father-in-law of the Islamic prophet Muhammad. Abu Bakr became the first openly declared Muslim outside Muhammad's family. Abu Bakr served as a trusted advisor to Muhammad.
Context: Abu Bakr attended the event of Ghadir Khumm, which took place a few months before Muhammad passed away. According to both Shia and Sunni sources, he was among the many who pledged allegiance to Ali at the event.  In Medina, after the Farewell Pilgrimage and the event of Ghadir Khumm, Muhammad ordered an army under the command of Usama bin Zayd. He commanded all the companions, except for his family, to go with Usama to Syria to avenge the Muslims' defeat at the Battle of Mu'tah. Muhammad gave Usama the banner of Islam on the 18th day of the Islamic month of Safar in the year 11 A.H. Abu Bakr and Umar were among those that Muhammad commanded to join Usama's army.  However, Abu Bakr and Umar resisted going under the command of Usama because they thought that he, who was 18 or 20 at the time, was too young to lead an army, despite Muhammad's teachings that age and standing in society did not necessarily correspond to being a good general.  In response to these worries, the Prophet said: "O Arabs! You are miserable because I have appointed Usama as your general, and you are raising questions if he is qualified to lead you in war. I know you are the same people who had raised the same question about his father. By God, Usama is qualified to be your general just as his father was qualified to be a general. Now obey his orders and go." Whenever Muhammad felt any relief from his fatal sickness, he would inquire as to whether Usama's army had left for Syria yet, and would continue urging his companions to leave for Syria. Muhammad even said, "Usama's army must leave at once. May Allah curse those men who do not go with him." However, while a few companions were ready to join Usama's army, many other companions, including Abu Bakr and Umar, disobeyed Muhammad's orders. It is also noted that this was the only battle expedition where Muhammad urged his companions to go the battle no matter what; for other battles, if someone was unable to go to the fight, Muhammad would let them stay at home.
Question: What happened after his death?
Answer: