In Progress

The history of magnetic digital data storage is beautifully documented here by Computer History dot org. Magnetic technology has been the primary method for storing the data since the first recorded device being a wire recorder publicized by Oberlin Smith in the Sept 8, 1888 issue of Electrical World.. Prior to that data storage with punch cards dates back to the mid-1700s.

Portable Storage Devices

The history of the floppy disc we are most familiar with is documented on Wikipedia and the timeline follows.

A notable figure is Alan Field Shugart (September 27, 1930 – December 12, 2006),an American engineer, entrepreneur and business executive whose career is said to have defined the modern computer disk drive industry.

year device size capacity maker description
1972 The Floppy Disc 8” 80 kB IBM A read-only, 8-inch-diameter (200 mm) flexible diskette called the “memory disk”.
1972 Memorex 650 8” 175 kB Memorex The first commercially available read-write floppy disk drive
1973 Diskette 1 8” ~250 kB IBM This disk format became known as the Single Sided Single Density or SSSD format. It was designed to hold the same amount of data as 3000 punch cards.
1976 Mini-floppy 5¼” 110 kB Shugart Associates The drive went on sale in late 1976 at a list price of $400, with a box of ten disks at $60. The new, smaller disk format was popular, and by 1978 ten different manufacturers were producing 5¼-inch drives.
1978 DSDD 5¼” 360 kB Tandon The double sided double density discs doubled the capacity.
1981 Floppy Disc Cartridge 3½” 218.8 kB Sony Besides adoption by Hewlett-Packard’s HP-150 of 1983 and Sony’s MSX computers that year, this initial design of a 3.33-inch (90mm x 94mm) format might have suffered from a similar fate as the other new formats; the 5¼-inch format simply had too much market share.
1984 HDD 5¼” 5-40 MB IBM The 5¼ HD drive was essentially a scaled-down 8-inch drive, using the same rotation speed and bit rate, it provided over three times as much storage as the 360 kB format, but had compatibility issues with the older drives due to the narrower read/write head.

Beyond floppy

year device size capacity maker description
1987 HD 3½” ~1.44 MB ? The term “1.44 MB” is a misnomer caused by dividing the size of 1440 kibibytes (1440 * 1024 bytes) by 1000, thus converting 1440 KiB to “1.44 MB” - where the MB stands for neither a megabyte (1,000,000 bytes) nor a mebibyte (1,048,576 bytes) but instead 1,024,000 bytes. Correctly dividing 1440 KiB by 1024 gives a size of 1.40625 MiB. These HD disks had an extra hole in the case on the opposite side of the write-protect notch.
1995 Zip Drive 97 x 98 x 6 mm 100, 250, 750 MB Iomega The format became the most popular of the superfloppy products, which filled a niche in the late 1990s portable storage market. Nonetheless, it was never popular enough to replace the standard 3+1⁄2-inch floppy disk. Zip drives fell out of favor for mass portable storage during the early 2000s as CD-RW and USB flash drives became prevalent.
1997 CD-RW n/a 700 MB Ricoh CD-RWs cannot be read in many CD readers built prior to the introduction of CD-RW. CD-ROM drives with a “MultiRead” certification are compatible.
1996 DVD na/ 4.7, 8.5, 17.08 GB Samsung The Digital Video Disc or Digital Versatile Disc is a digital optical disc data storage format. It combines technologies developed by two camps: one being Philips and Sony (developers of the CD and CD-i), and the other supporting the Super Density (SD) disc: Toshiba, Time Warner, Matsushita Electric, Hitachi, Mitsubishi Electric, Pioneer, Thomson, and JVC.
2002 USB ThumbDrive n/a ~128 GB, 512 GB, 2 TB Trek 2000 International1  

USB Drive Inventor Debates

There was contention over who invented the usb flash drive. Wikipedia includes details.