The dmesg command can be used to view events that occurred during boot, such as the hardware configuration.

[user1@server1 ~]# dmesg
[ 9996.979046] usb 1-5: SerialNumber: 20071114173400000
[ 9996.984117] ums-realtek 1-5:1.0: USB Mass Storage device detected
[ 9996.998449] scsi host16: usb-storage 1-5:1.0
[ 9996.998663] usb 1-5: USB disconnect, device number 14
[ 9998.040055] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[ 9998.067604] ata1.00: configured for UDMA/133
[ 9998.247066] init: anacron main process (8404) killed by TERM signal

Also, the /var/log/boot.log file has information related to boot.

[user1@server1 ~]# cat /var/log/boog.log | less * 
speech-dispatcher disabled; 
edit /etc/default/speech-dispatcher * VirtualBox Additions disabled, not in a Virtual Machine
saned disabled; edit /etc/default/saned * Restoring resolver state...[ OK ]
 * Stopping System V runlevel compatibility[ OK ]
 * Starting Mount network filesystems[ OK ]
 * Stopping Mount network filesystems[ OK ]

The who --boot command can be used to display the date and time the system was booted.

[root@server1 ~]# who --boot
system boot 2017-04-14 17:48

 Similarly, the uptime command can be used to show how long the system has been up.

[root@server1 ~]# uptime
02:37:41 up 1 day, 23:55, 1 user, load average: 0.05, 0.06, 0.14